THE SPOROZOA 



203 



N. beaucoudrayi ; D. aphroditae (Lank.), from the gut of Aphrodite (Fig. 



19) ; and other species. 



The following genera of Cephalina are of uncertain position : 

 Genus 67. Nematoides, Mingazzini, 1891. Trophozoite vermiform, 



without septum ; epim. in form of a fork or pair of pincers, borne on an 



elongated neck. Unique species N. fusiformis, Ming., from the gut of Bal- 



Fio. 46. 



Selenidium, various species, a, comma -shaped species (" Selenidium en virgule ") from 

 Cirratulus cirratvs ; ep, minute epimerite, afterwards thrown off. b, semicolon-like species 

 ("6 1 . en point et virgule") from the same host, with very large epimerite. c-f, stages of S. 

 eehinatum, C. and M. (par Dodecaceria concharwin). c, free sporont ; d, syzygy of two sporonts ; 

 e, a spore, external view, showing the spiny surface ; /, a spore in section, showing the four 

 sporozoites. a and 6, x 500 ; c and d, x 300 ; e and/, x 850. (After Caullery and Mesnil.) 



anus perforatus and Pollicipes cornucopia. Genus 68. Ulivina, Mingazzini, 



1891. Body of elliptical form, protom. a quarter the length of the body. 

 The external membrane forms a continuous sac round the animal. U. 

 elliptica, Ming., from the gut of Audouinia filigera. Genus 69. Syria, Le"ger, 



1892. Epim. knobbed, bordered by a thick ring (Fig. 17, b). Protom. 

 subspherical ; deutom. conical ; with numerous enclosures. S. inopinata, 



