Sporozoa 287 



crustacean host. After gymnospores reach a suitable mollusc, development 

 results in sporozoites (Fig. 6. 10, A-D), one from each zygote, as described 

 above. 



The family includes two genera (42): Nematopsis Schneider (Fig. 6. 10, H) with 

 monozoic spores, from crabs; and Porospora Schneider (Fig. 6. 10, F, G), with naked 

 sporozoites, from lobsters. 



Family 11. Stenophoridae. The epimerite is rudimentary or absent. 

 Early syzygy is unknown. Ovoid spores are released by rupture of the 

 gametocyst. 



Two genera are included (66): Fonsecaia Pinto and Stephanophora Labbe (15; Fig. 6. 



Family 12. Stylocephalidae. The epimerite ranges from globular or dis- 

 coid to a complex elongated or conical organelle, sometimes lobate or 

 equipped with bristles. Early syzygy is unknown. A pseudocyst is reported 

 for some genera. Spores may be released in chains. 



The following genera are included (66): Bulbocephalus Watson (Fig 6 9 L) 

 Cystocephalus Schneider (Fig. 6. 9, I), Lophocephalus Labbe, Oocephalm Schneider. 

 Sphaerorhy7ichiis Labbe, Stylocephalus Ellis (Fig. 6. 9, M). 



Suborder 2. Acephalina 



These are non-septate, mostly coelomic parasites, many of which occur 

 in the seminal vesicles of oligochaetes. Some of the exceptions are Hy- 

 pendion (86), a genus of uncertain taxonomic status, including intestinal 

 parasites of echiuroid worms; and Lankesteria and Allantocystis, from the 

 digestive tract of insects. A synoptic review of genera and families is 

 available (10). 



Family 1. Aikinetocystidae. The family contains Aikinetocystis Gates 

 (Fig. 6. 1, F), in which the anterior end of the trophozoite is dichoto- 

 mously branched, with sucker-like organelles at the tips. Trophozoites 

 may reach lengths of 3-4 mm. Spores are similar to those of Monocystis. 



Family 2. Allantocystidae. This family was established for Allantocystis 

 Keilm (67), in which the elongated trophozoites undergo head-to-head 

 syzygy. The gametocyst is much elongated (Fig. 6. 11, F). Spores are 

 spindle-shaped, not quite symmetrical. 



Family 3. Diplocystidae. Early syzygy may or may not occur. Spores 

 (Fig. 6. 4, M) are ovoid to spherical. A small pseudopodial epimeritic 

 organ may be present. Species are known from flatworms, insects and 

 tunicates. 



FijTfr Td)"'' '"'^"'^^''- ^'P^^^yf^' Kunstler (62) and Lankesteria Mingazzini (112; 



