SPECIAL MORPHOLOGY AND TAXONOMY OF SPOROZOA 438 



47. Genus SpJicerocystis, Labb^ (1899). Epimerite a small sphere or ellip- 



soid at the end of a long slender neck; gut of Cyphon palUdulus. 



48. Genus Lophocephalm, Labbe (1899). Epimerite large, sessile flat and 



cup-like disc with crenulate margin and numerous upright digiti- 

 form processes; sporoblasts black and hat-shape; gut of Helops 

 striatus. 



49. Genus Cystocephalus Schn. (1886). Epimerite a large lance-shape papilla 



set on a short stout cjdindrical neck; sporoblasts of irregular shape; 

 gut of Pimelia sp. 



Family 8. Menosporidae, Leger (1892). Gamonts solitary; epimerite a 

 large cup bordered with hooks and placed on a long slender neck; sporo- 

 cysts open by simple rupture; sporoblasts crescentic, smooth. 



50. Genus Menospora, L^ger (1892). Characters of the family; gut of 



Agrion sp. 



Order 2. Schizogregarinida, Leger (1892). 



The Schizogregarinida are parasites of the digestive tract and 

 appended organs of arthropods, annelids and tunicates. They 

 differ from the Eugregarinida in having an asexual or multiplicative 

 cycle, the sporozoite growing into an agamont either as an intra- 

 cellular or an extracellular parasite. Asexual reproduction occurs 

 by division, internal budding or by multiple division. The life 

 history, gamete formation and metagamic divisions of the zygote 

 vary widely and no characteristic difference marks the sporoblasts 

 from those of the Eugregarinida. Change of hosts is safely estab- 

 lished for only one type— the Porosporidee. According to the pres- 

 ence of one or of more than one sporoblast in a sporoc\'st Leger and 

 Duboscq divide the group into subdivisions, the Monospora and 

 the Polyspora. Systematically this is preferable to the subdivisions 

 into Entoschiza and Ectoschiza as suggested by Fantham on the 

 basis of the mode of parasitism of the young stages. Owing to 

 absence of information in connection with the life history of the 

 majority of forms it seems wiser at present to follow Doflein in 

 cutting out further subdivisions entirely except for the families as 

 follows. 



Family 1. Ophryocystidae, Leger and Duboscq (1900). These are the 

 best known of all the schizogregarines, the full life history having been 

 worked out by Leger (1907). They are extracellular parasites of the Mal- 

 pighian tubules of beetles with asexual reproduction by simple or multiple 

 division. The single sporoblast (see above p. 424) is characteristic but its 

 structure differs in the many different species. The sporoc3^st membrane is 

 single or multiple (Fig. 184) and the number of sporozoites is eight. 

 1. Genus Ophryocystis, A. Schneider. With the characters of the family. 



Family 2. Schizocystidse, Leger and Duboscq. Cylindrical or elongated 

 with a differentiated anterior end. Agamogony b}' midtiple division, extra- 

 cellular. Pseudoconjugation, gamete formation and sporoblast formation 

 with eight sporozoites, as in Eugregarinida, 

 28 



