Phylum Fungilli [221 



The spore-forming structure (sporoblast) is a protoplast with several nuclei; it is 

 either a whole small plasmodium, or half of one, or a protoplast cut out endogen- 

 ously within a plasmodium. Two of the nuclei are set apart in cells which become 

 converted into the valves of the spore. Two or four are set apart in cells which become 

 converted into polar capsules. Two, of which it is established that they have two 

 chromosomes each, are the nuclei of the infective protoplast. 



In a review of the literature as to Hfe cycles, Noble (1944) remarks as follows. "A 

 survey of the literature reveals that there is little agreement on the details of nuclear 

 changes in the Myxosporidia. Some authors maintain that the cycle is mainly haploid, 

 others have described a diploid cycle. Some reports indicate that there are two reduc- 

 tion divisions and two zygotes in one cycle. When only one zygote is reported the 

 reduction division in one case occurs just before fertilization, in another case it occurs 

 just after fertilization. Some authors have maintained that there is no sexual process." 

 Noble's own conclusions include the following. The organisms are diploid at most 

 stages. The meiotic divisions are among those by which the sporoblast becomes multi- 

 nucleate. The two haploid nuclei of the spore, which unite after germination, are 

 derived from a single diploid nucleus. Authors who have described fusions of proto- 

 plasts, or transfers of nuclei from one protoplast to another, have had no evidence 

 beyond an understandable unwillingness to accept fusions of sister nuclei. 



Nearly two hundred species of the present order are listed in the monograph of 

 Kudo (1920), who established three suborders. 



A. Valves conical, spores biconic (suborder Eurysporea Kudo). 



Family 1. Myxoceratida nom. nov. Family Ceratomyxidae Doflein Protozoen 182 

 (1901), based on a generic name which is a later homonym. Characters of the sub- 

 order. Myxoceros nom. nov. [Ccratomyxa Thelohan 1892, non Ceratiomyxa Schroter 

 1889; if ever names are homonymous without being absolutely identical, these are.) 

 Some thirty-five species; the type is M. sphaerulosa (Thelohan) comb, nov.; Noble 

 studied mitosis in M. Blennius (Noble) comb. nov. Leptotheca, Myxoproteus, War- 

 dia, Mitraspora. 



B. Valves hemispherical, spores spherical (suborder Sphaerosporea Kudo) . 

 Family 2. Chloromyxida [Chloromyxidae] Gurley in Bull. U. S. Fish Comm. 1 1 : 



418 (1893). Chloromyxees Thelohan in Bull. Soc. Philomath. Paris ser. 8, 4: 176 

 (1892). Chloromyxea Braun in Centralbl. Bakt. 14: 739 (1893). With four polar 

 capsules. Chloromyxum. 



Family S.Sphaerosporida [Sphaerosporidae] Davis 1917. With two polar cap- 

 sules. Sphaerospora, Sinuolinea. 



C. Valves saucer- or boat-shaped, spores disk-shaped or fusiform (suborder 

 Platysporea Kudo ) . 



Family 4. Myxidiida [Myxidiidae] Gurley op. cit. 420. Myxidiees Thelohan op. 

 cit. 175. Myxidiea Braun I.e. Myxidium, Sphaeromyxa, Zschokkella. 



Family 5. Coccomyxida [Coccomyxidae] Leger and Hesse 1907. Coccomyxa. 



Family 6. Myxosomatida [Myxosomatidae] Poche in Arch. Prot. 30: 230 (1913). 

 Myxosoma, Lentospora. 



Family 7. Myxobolida [Myxobolidae] Gurley op. cit. 413. Myxobolees Thelohan 

 op. cit. 176. Myxobolea Braun I.e. Myxoboliis, Henneguya, Hoferellus. 



Order 2. Actinomyxida Stole 1911. 



This order includes about a dozen parasites in annelid worms. A plasmodial stage 

 and asexual reproduction are believed not to occur; the infective protoplast grows 



