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Notes: SYNOPSIS. All zoologists are affected by provisions in the very recently published International Code of Zoological Nomenclature, the first revised edition of these important rules to appear in over 50 years. Common nomenclatural practices, often malpractices, of protozoologists and parasitologists who work primarily in taxonomic fields are revealed and discussed in light of recommendations and mandatory regulations to be found in the new Code. Some errors have been due solely to carelessness; others have involved misinterpretations of various directives; still others have involved cases not adequately covered by the old Règles. Certain mistakes of the past cannot be changed; but others are to be rectified upon discovery, according to mandates in articles of the new Code. Practical applications of the rules of nomenclature are stressed, and examples are taken from actual situations found to exist throughout all major taxa of the phylum Protozoa.Because of the value of such discussion in both new and revisory work in protozoan systematics, the following major topics are given special consideration: matters of orthography, the original spelling of names and their justified or unjustified emendation; authorships and dates of names, who is responsible and when, and how such data are properly cited; mandatory dates in the new Code, and their effect on both already established names and names not yet proposed; the principles of priority and conservation or continuity, and how the rules attempt to satisfy proponents of both of these diametrically opposed “laws”; the concepts of synonymy and homonymy, and proper methods of treating names which have become involved in such situations; family-group names, and the several special nomenclatural problems they present to protozoan taxonomists; the major problem of types, and the peculiar position of protozoologists with regard to the type concept, especially type-specimens for categories in the species-group; miscellaneous considerations, several unrelated but significant topics not appropriate for inclusion in preceding sections of the paper.

Notes: Over ninety genera of ciliated protozoa have been given names preoccupied by the generic names of other animal organisms. To date some sixty of these junior homonyms never have been corrected. In half of these cases the homonymous ciliate names have been buried as synonyms of one kind or another, however, and need be of no further practical concern. For the remaining genera, thirty in number, replacement names arc proposed in the present paper in accordance with provisions of the International Rules of Zoological Nomenclature. Such action is considered to be in the best interest of ultimate taxonomic stability among the groups of organisms involved. New names also have had to be proposed for five families or subfamilies whose type genera have lost their original names through homonymy.

Notes: SYNOPSIS. Morphogenesis in the small holotrich ciliate Pseudocohnilembus persalinus has been found to be more complex than that reported to date for any other hymenostome species, at least with respect to the major phenomenon of stomatogenesis. Formation of two anlagen or fields of proliferating kinetosomes in the vicinity of the old oral area initiates the highly autonomous process. Subsequently a number of separate but coordinated morphogenetic movements occur which involve not only the new anlagen and their extraordinary growth and fragmentation but also the bases of the “old” ciliary buccal organelles.Particularly indispensable in our investigation was the Bodian protargol technique which reveals the external ciliature of a properly fixed organism as well as components of its infraciliature. The Chatton-Lwoff silver impregnation method, however, was also very useful in the overall comparative study of the present and related species of ciliates.At one stage in stomatogenesis of Pseudocohnilembus persalinus there is clear evidence of a basic tetrahymenal plan of organization of the buccal ciliature, even though this is not at all apparent in the mature, non-dividing ciliate. Such a revelation underlines the significant value of morphogenetic studies in comparative ciliate systematics, for our findings permit retention of the genus Pseudocohnilembus in the suborder Tetrahymenina of the holotrich order Hymenostomatida. At the same time, however, they necessitate revision of some currently held concepts in the fields of ciliate morphology, taxonomy, and phylogeny.

Notes: SYNOPSIS. An international collection center for type-specimens of protozoa belonging to the subphylum Ciliophora has been set up at the University of Illinois through the cooperation of the Museum of Natural History there. The writer will act as curator of slides deposited in this central collection. Syntypes are solicited from all protozoologists interested in ciliate taxonomy who may possess such specimens. In accordance with provisions of Article 72 of the International Code of Zoological Nomenclature, all material received will be properly handled and indexed and regarded as “the property of science”; preparations will be made available on loan to qualified workers anywhere who need them temporarily for research purposes. Existence of such a type-slide collection should aid in alleviation of a growing number of vexatious problems in the systematics of the ciliate Protozoa at specific and generic levels.

Notes: SYNOPSIS. Stomatogenesis or new mouth formation sensu lato repnts an explicit example of a major morphogenetic phenomenon le life cycle of most ciliate Protozoa. Investigations of the process a number of approaches may yield data of considerable value. The present paper 3 such approaches are treated in some detail.udies of stomatogenesis can be of importance in providing addial information of significance on the structure and physiology a given organism. Five major types or categories of stomatoesis in ciliates are recognized. These are defined and discussed. search related to such an intrinsic value of the phenomenon the K carried out is generally only descriptive, and the most importechnic employed is some method of silver impregnation.a comparative approach is used, then attention may be focused possible homolegies in stomatogenesis as it occurs in diverse ies of ciliates. Such data are (or potentially are) of value not in the practical taxonomy of the organisms involved but also onsideration of phylogenetic and evolutionary interrelationships ing the higher groups comprising the entire subphylum Ciliophora. Such application of comparative studies may well become a very fruitful approach to certain problems in ciliate phylogeny; 2 examples are discussed briefly. Silver impregnation technics are again indispensable.Perhaps stomatogenesis will prove most valuable in the hands of developmental biologists who are seeking to solve 2 of the most intriguing problems in cell biology today: the exact origin of new kinetosomes (or centrioles), and their precise morphogenetic role in the life cycle of a cell or unicellular organism. Since this third approach to the study of stomatogenesis is of necessity a dynamic one, the researcher must employ sophisticated experimental technics to obtain data at the molecular and macromolecular levels of both organization and function. Some progress in this area has already been made, but the availability of “ideal” organisms has perhaps not been as widely realized as it should. Certain of the “higher” ciliates have a mode of stomatogenesis which would lend itself beautifully to fruitful investigation of problems concerning both replication or neoformation of kinetosomes and their possible role in fibrillogenesis in unicellular organisms.

Notes: SYNOPSIS. Confusion has long existed in the literature concerning both the taxonomy and the nomenclature of ciliates belongin: to the astomatid family Haptophryidae. Most of the controversy has centered around the names and concepts of “Haptophrya” and “Sieboldiellina.” The latter name, widely used for certain species found as parasites (endocommensals) of turbellarians, must fall as a junior synonym of the former, which has commonly been restricted to the astomatous ciliate parasites (endocommensals) of various amphibians But the species of “Haptophrya” are then left without a generic vehicle, since Haptophrya Stein, 1867, must, in effect, be used to replace Sieboldiellina Collin, 1911, as the proper generic name of the turhellarian parasites Fortunately a name is available for the amphibian species: Cepedietta Kay, 1942.The problem is further complicated because of the recognition of subfamilial groups, the name of one of these having been formed from Sieboldiellina and having become associated with certain species parasitic in turbellarians. With the realization that, by the international rules of zoological nomenclature, Haptophrya must be used with reference to these particular turbellarian parasites, the subfamilial name associated with the amphibian forms must be changed. We propose Cepediettinae n. nom. in solution of this particular problem. We recognize a third subfamily, Ckpkde's Lachmannellinae, to contain the three remaining acceptable genera comprising the family Haptophryidae: Anndophrya, Lachmanndla, and Steinella.At the generic and specific levels numerous errors of a nomenclatural nature have been committed in the older literature, many unwittingly perpetuated in recent papers. These are all corrected in the present work. For the sake of future clarity we have included a series of figures, both original and from the literature, and have designated neotypes of the two principal species involved in the overall controversy.

Notes: SYNOPSIS. In the first use of electron microscopy in a comparative investigation of ciliates belonging to the order Thigmotrichida, ultrastructural data were collected on ciliary organelles of the buccal area. Species studied included members of the genera Ancistrum and Boveria. Analysis of the findings suggest close affinities between thigmotrich and peritrich ciliates. Further comparison with studies on hymenostome (sensu lato) ciliates supportes the hypothesis of a common ancestral stock in the phylogenetic history of all 3 of these groups. Structures very likely homologous in species of hymenostomes, thigmotrichs, and peritrichs include: the undulating membrane, the polykineties, the oral ribs, the filamentous reticulum, and a small field of barren kinetosomes.

Notes: SYNOPSIS. A sequence of developmental stages of Plistophora hyphessobryconis Schaperclaus, a microsporidian protozoan parasite of the muscular tissue of several species of freshwater fishes, was studied with the electron microscope. The youngest stages observed, ca. 4 × 2 μ, have a single nucleus and their plasm contains only ergastoplasmic lamellae and ribosomes. They are surrounded by a halo of lysed host tissue. They increase in volume to become large sporonts with a great number of nuclei and a thick, 2-layered membrane. Thru schizogony, a corresponding number of sporoblasts is produced within this pansporoblast membrane. Sporoblasts start to develop a thick spore membrane, and a number of smooth-membraned vesicles appear in the plasm. These vesicles fuse to make the outer membrane of the filament. Later, its inner structures originate—the axial electron-dense substance, filling the hollow lumen of the filament, and a middle, electron-transparent layer. The structure of the filament is discussed in relation to its function and with regard to the findings of other authors.The polaroplast is a laminated structure, originating possibly by transformation of endoplasmic reticulum; the polar cap forms its apical part. The cap is also lamellar; its substance reaches into the lumen of the filament for a certain distance. No micropyle was discovered in the shell; the filament is fastened to the polar cap. These observations on microsporidian development and on the structure of their spores are compared with similar data on myxosporidian species. Such a comparison speaks clearly in favor of the complete taxonomic separation of the Microsporidea from the Myxosporidea, the latter being quite different also from other sporozoa sensu lato.

Notes: SYNOPSIS. The unusual patterns of infraciliary kinetosomes on the body and in the large anterior depression of the trophont stage of this difficult-to-classify ciliate have been examined by use of the Chatton-Lwoff silver impregnation technique. In our material there are nine rows of somatic cilia, arranged more or less concentrically around the oral cavity at the anterior end of the pyriform-shaped body; in the cavity itself there are eight quite separate rows of “vestibular” ciliature. Erratically distributed on posterior areas of the body are argentophilic “granules” which may be non-cilia-bearing kinetosomes. A contractile vacuole pore, described for the first time, is located on the ventral surface in the posterior third of the body to the right of the midline.Still more information is needed to be able to establish the most appropriate taxonomic allocation for Cyathodinium. It is suggested that a combination of fine structural (electron microscopical) and morphogenetic (fission, stomatogenesis, reorganization) studies is required to elucidate both the form and the function of the several unique features of Cyathodinium and that a new understanding of these will permit resolution of the problem of the systematic status of the ciliate.

Notes: SYNOPSIS. Two species of the taxonomically enigmatic genus Cyathodinium, C. piriforme and C. cunhai, were studied in some detail at both light and electron microscopic levels. Data obtained strongly suggest suctorian affinities for the genus, since a number of structures or features are strikingly reminiscent of similar (if not homologous) structures recently discovered in ciliates belonging to the order Suctorida.Endosprits (suctorial tentacles?) of Cyathodinium show an arrangement of microtubules not unlike that known for several suctorians, especially Acineta and Tokophrya. Haptocysts or missile-like bodies, ca. 600 mμ long, have been observed within endosprits and free in the cytoplasm; again this is reminiscent of the complex organelles recently described from several suctorian groups. Mouthlessness, coupled with the presence of a ventral depression (functioning in gathering prey at distal ends of endosprits?) and the presence of food vacuoles in the cytoplasm, further support a suctorian mode of feeding. Finally, stages in the curious life cycle of Cyathodinium suggest neoteny and a basic similarity to endogenous budding processes in certain suctorians.