218] The Classification of Lower Organisms 



Family 3. Didymophyida [Didymophyidae] Wasilewski 1896. Family Didymo- 

 phyiden Stein (1848). Like the foregoing, but the cells extremely elongate. Didymo- 

 phyes. 



Family 4. Acanthosporida [Acanthosporidae] Labbe in Thierreich 5: 27 (1899). 

 The spores with polar or equatorial bristles. Acanthospora. 



Family 5. Stylocephalida [Stylocephalidae] Ellis 1912. Family Stylorhynchidae 

 Labbe op. cit. 30, based on a generic name which is a later homonym. Epimerite 

 elongate with a small terminal knob. Stylocephalus. 



Family 6. Actinocephalida [Actinocephalidae] Wasilewski 1896. Epimerite with 

 thorns. Numerous genera, Sciadophora, Acanthorhynchus, Actinocephalus, Hoplo- 

 rhynchus, Pileoccphalus, etc. 



Family 7. Menosporida [Menosporidae] Labbe op. cit. 29. Epimerite with a long 

 stalk, distally branched and bearing appendages. Menospora. 



Family 8. Dactylophorida [Dactylophoridae] Wasilewski 1896. Epimerite dis- 

 tally broadened, clinging to the host epithelium by means of numerous filiform pro- 

 cesses. Dactylophorus, Nina [Pterocephalus), etc. 



Family 9. Porosporida [Porosporidae] Labbe op. cit. 7. Heteroecious: in Porospora, 

 the gregarinoid stage occurs in crabs and the production of spores occurs in mussels. 

 The spores contain a single sporozoite and open through a pore. 



Order 8. Haplosporidiidea Poche in Arch. Prot. 30: 178 (1913). 

 Order Aplosporidies Caullery and Mesnil 1899. 

 Order H aplosporidies Caullery and Mesnil in Arch. Zool. Exp. Gen. ser. 4, 4: 



104 (1905). 

 Order Haplosporidia Auctt., the mere plural of a generic name. 

 Subclass Haplosporidia Hall Protozoology 326 (1953). 

 Unicellular intracellular parasites, the cells becoming multinucleate and multiply- 

 ing by fragmentation, producing walled spores which germinate by releasing the 

 protoplasts as single sporozoites. 



The vegetative body is of the type properly called a plasmodium. The nuclei and 

 the process of division, described by Granata (1914) are characteristic. The resting 

 nucleus contains an "axial rod" as well as a nucleolus-like body. In mitosis the axial 

 rod becomes converted into an intranuclear spindle. Individual chromosomes have 

 not been seen; the chromatin gathers in a mass about the middle of the spindle (the 

 figures are curiously diatom-like). The mass of chromatin, the nucleolus-like body, 

 and the entire nucleus, divide by constriction; the ends of the spindle persist as the 

 axial rods of the daughter nuclei. Eventually, the plasmodium secretes a thin wall 

 and the protoplast divides into uninucleate naked cells. Granata found that these 

 cells are gametes, and that conjugation takes place among gametes produced by the 

 same plasmodium. The zygotes become walled spores which germinate by casting 

 off a circular operculum and releasing the contents. If the life cycle is correctly 

 understood, we may suppose that these organisms are degenerate gregarinos. 



In the present state of knowledge, it will be as well to treat the typical haplo- 

 sporidians as a single family: 



Family Haplosporidiida [Haplosporidiidae] Caullery and Mesnil in Arch. Zool. 

 Exp. Gen. ser. 4, 4: 106 (1905). Families Bartramiidae and Coelosporidiidae Caul- 

 lery and Mesnil op. cit. 107. Characters of the order. Haplosporidium (spores with 

 appendages at both ends) and Urosporidium (spores with a single appendage) attack 



