THE SPOROZOA 



195 



body except at the anterior extremity. Spores not described. Type 

 0. phronimae, Frenz., from the gut of Phronima sedentaria. Genus 1 6. 

 Ancora, Labbe", 1899 (nom. nov. for Anchorina, Ming., 1891, preoccupied). 

 Trophozoite anchor-shaped, with two anterior lateral prolongations of the 



FIG. 39. 



Lithocystis schneideri, Giard (par. Echinocardium, etc.). a, an association of two of the 

 extremely lively trophozoites, which attach themselves loosely to one another in pairs, keeping 

 up at the same time very active movements. 6, two trophozoites (sporonts) about to become 

 encysted ; the bodies have contracted into compact motionless masses, and in each individual 

 vacuoles have appeared containing clinorhombic crystals of calcium oxalate ; the whole mass 

 is surrounded by a coat of amoebocytes from the coelomic fluid of the host, c, an unripe 

 spore, before formation of sporozoites, highly magnified, d, a ripe spore, c and d also show 

 the differences between the two kinds of spores ; e is a microspore, rf, a macrospore. n, 

 nucleus ; am.c, investment of amoebocytes ; cr, crystals ; /, funnel-like prolongation of the 

 epispore, through which the sporozoites pass out ; t, tail-like process of the epispore, tubular 

 in the unripe, filamentous in the ripe spore ; sp.z, sporozoites. (After Leger.) 



body. Spores unknown. Unique species A. sagittata (Leuck.), from the 

 gut of Capitella capitata. 



The following genera of Acephalina, known only in the trophozoite 

 phase, are insufficiently characterised : 



Genus 17. Pleurozyga, Mingazzini, 1891. Trophozoites more or less 

 claviform, associating laterally. Three species from Ascidians. Genus 18. 



