124 ILLINOIS BIOLOGICAL MONOGRAPHS [334 



Ellis replaced this species in the genus Gregarina although the only 

 known diagnostic character, the epimerite, does not coincide with that 

 of the genus. This structure does, however, agree in shape with that of 

 the genus Pileocephalus according to Schneider (1875:591) and Labbe 

 (1899:19): "Epimerite regulier simple conoide ou en fer de lance" 

 and I have replaced it in the genus Pileocephalus. 



ACTINOCEPHALUS FIMBEIATUS (Diesing) Watson 

 [Figures 189, 190] 



1853 Gregarina Locustae Carolinae Leidy 1853 :239 



1856 Gregarina Locustae carolinae Leidy 1856 :47 



1859 Gregarina fimbriata Diesing 1859 :730 



1903 Stephanophora locust aecarolinae Crawley 1903 :54 



1907 Stephanophora pachyderma Crawley 1907 :226 



1913 Actinocephalus pachydermus Ellis 1913b :278 



1916 Actinocephalus fimbriatus Watson (This paper) 



Actinocephalus: Sporonts solitary, obovate. Maximum length of 

 sporonts 500/t. Protomerite hemispherical, not constricted at septum 

 but contour continuous with that of deutomerite. Latter tapers slightly, 

 ending in a blunt point. Sarcocyte very thick, especially over anterior 

 end of protomerite. Endocyte black in deutomerite, less dense in proto- 

 merite. Nucleus spherical with 12 or more small karyosomes. Epimerite 

 an inverted campanula, sessile, with ten or more slender digitiform pro- 

 cesses directed upward along the periphery. 



Cysts and spores unknown. 



Taken at Wyncote, Pa. Host: Dissosteira Carolina (L.) : Habitat: 

 Intestine. 



A cephalont of this species was first seen by Leidy in 1853. He 

 described it and the sporonts of Gregarina locustae carolinae together 

 under the latter name. 



In 1903, Crawley renamed the species Stephanophora locustaecaroli- 

 nae from the character of the epimerite, as drawn by Leidy. Crawley 

 did not see the species then. The error of inclusion was discovered by 

 Crawley from new material in 1907, and he then separated the two spe- 

 cies, describing each in detail. The former he called Stephanophora 

 pachyderma, the latter by the original name. 



The first binomial name given to this species, however, was Gregarina 

 fimbriata, which Diesing used. He redescribed Gregarina locustae caro- 

 linae of Leidy under a new name adding no new material. He says of 

 this species "proboscis digitato-fribriato", which definitely places his 

 description. 



