628 PROTOZOOLOGY 



longer cilia; 2 adoral ciliary rows on right of peristome, curved dor- 

 sally behind cytostome; contractile vacuole posterior; macronucleus 

 single or divided into as many as 7 parts ; micronucleus ; commensal. 



A. choanomphali C. (Fig. 295, c). 55-90ju by 18-20ju; in the mantle 

 cavity of Choanomphalus sp. 



Genus Ancistrospira Chatton and Lwoff. Ciliation meridional to 

 spiral; peristome right spiral; commensal. 



A. veneris C. and L. 50-60^ by 22-28^1; ovoid, anterior end 

 pointed; ciliary rows meridional; thigmotactic field on the left side, 

 sharply marked from body ciliation; on the gills of Venus fasciata. 



Genus Boveria Stevens {Tiarella Cheissin). Conical; cytostome 

 at posterior end; peristome spiral posteriorly; macronucleus oval, 

 in anterior half; a micronucleus; contractile vacuole posterior; ecto- 

 commensal on gills of various marine animals such as Teredo, Bankia, 

 Tellina, Capsa and Holothuria. Several species. 



B. teredinidi Pickard (Fig. 295, d). 27-173m by 12-3 1^; on gills of 

 Teredo navalis; California. 



Genus Plagiospira Issel. Conical; anterior end attenuated; peri- 

 stome runs spirally from middle of body to cytostome, with long 

 cilia; marcronucleus oval, anterior; a micronucleus; contractile vacu- 

 ole near middle of body; somewhat spirally arranged striae widely 

 apart on right side; commensal, 



P. crinita I. (Fig. 295, e). 32-58/i bj^ 18-34jli; in Cardita calyculata 

 and Loripes lacteus. 



Genus Hemispeira Fabre-Domergue. Nearly spherical; flattened; 

 longitudinal non-ciliated furrow on ventral surface, which encircles 

 thigmotactic posterior cilia; 4-5 cross-furrows of cilia; a huge adoral 

 membrane at anterior end; macronucleus, micronucleus large; con- 

 tractile vacuole, anterior-right; commensal. 



H. asteriasi F.-D (Fig. 295, /). 20-30/i long; ectocommensal on 

 Asterias glacialis. 



Genus Hemispeiropsis Konig. Oval; body surface not ciliated, 

 except the adoral end which bears 1-2 cross-rows of cilia and thig- 

 motactic cilia; adoral membrane double; macronucleus large, spheri- 

 cal, with an imbedded micronucleus; contractile vacuole central; 

 ectocommensal. 



H. comatulae K. About 23-27m long, excluding membrane; on 

 Comatula mediterranea. 



Family 5 Sphenophryidae Chatton and Lwoff 



Genus Sphenophrya Chatton and Lwoff. Triangular to crescentic; 

 in mature state, basal rows of cilia distinct on the broad side, con- 



