36 ILLINOIS BIOLOGICAL MONOGRAPHS [36 



est below mid-region, with characteristic specialized crescentic zone at 

 apex, with what appears to be a canal leading from apex a short distance 

 into protomerite. Deutomerite cylindrical, blunt at posterior end. No 

 constriction at septum. Nucleus ovoidal with one large karyosome. 

 Development extracellular. Epimerite atypical for that of the genus, 

 but still Pyxinia-like, a long style reaching in large trophozoites to base 

 of the cell and having a large crenulated cup-like enlargement at its mid- 

 point, the rim of the cup being turned away from the body of thegregarine. 



Cysts spherical, 85 to lOOju in diameter. Spores unknown. 



Intestine of Cthamalus stellatus Ranzani. 



Taken at Cette, France. 



In the first mention of the species, Leger and Duboscq 1909:112, the 

 spelling is given as chtamali and that of the host genus chtamalus, while 

 on pp. 114 and 115 the spelling is chthamali and chthamalus. Tregouboff 

 gives it for both parasite and host as cthamali (us). 



Family CEPHALOIDOPHORIDAE Kamm 1922 



Intestinal parasites of Crustacea, development intracellular, early 

 syzygies of two sporonts. Cysts without sporeducts, spores ovoidal with 

 equatorial line. Entire life cycle passed within a single host. 



DISCUSSION OF THE NEW FAMILY CEPHALOIDOPHORIDAE 



The genus Cephaloidophora was created in 1908 by Mawrodiadi for 

 intestinal parasites of the Crustacea. Leger and Duboscq in 1907 created 

 a genus in all respects identical with the former genus naming it Frenze- 

 lina; but in 1911 they discovered that the name Frenzelina was preoccu- 

 pied, so the name Cephaloidophora becomes the accepted genus designa- 

 tion. 



The genus Frenzelina had been placed with the Gregarinidae because 

 of the precocious association of sporonts in pairs; but there the simi- 

 larities stop. Cephaloidophora was placed in the family Stenophoridae 

 (Sokolow 1911:286) and it must be acknowledged that there are many 

 characters in common with that family, including (a) intracellular devel- 

 opment, (b) rudimentary epimerite, (c) spores ovoidal with equatorial line, 

 (d) cysts without spore-ducts, (e) spores not united in chains. (A) is 

 confined to these two groups alone, in both of which there is cell-destruc- 

 tion, all other known forms possessing extracellular trophozoitic stages 

 without or with but little injury to the host. The only important variance 

 in the two groups lies in the fact that the Cephaloidophoridae invariably 

 form early syzygies of two individuals while the Stenophoridae as invari- 

 ably do not. The shape of the body, usual shape and character of the 

 nucleus and texture of the protoplasm are different in the two groups. 

 For complications given below, the gregarines of the Crustacea should be 

 considered apart from all others, at least until many of the knotty points 



