INFUSORIA 63 



0. bifaria Stokes (Fig. 112). Body broad; longtli .2 mm.; bristles 

 in a single line: in fresh water. 



9. Stylonychia Ehrenberg-. Body elliiitical, 

 rigid; oral groove triangular or semicircular, reach- 

 ing middle of body ; cilia and bristles as in Oxytriclia; 0lfi 

 usually 3 long caudal bristles present: 

 G species; in fresh and salt water; A^ery 

 ^^^Mf common, the animals often moving by -fc a-^ y 

 •i^Ms^l quick jerks. *^ ^ /m 



^'^[ S. pustulata Ehr. Body broad; ^ « 



^'^ISS length .25 mm.; width .1 mm.: in ^h ^ 



^^!^w infusions. %fcrvi 



S. mytilus (0. F. Miiller) (Fig. 

 Fig 112 113). Body broadest in front of 



OxyMcha middle; length .3 mm.: in fresh Fig. 113 



hi f aria „,of^,. Stylonychia 



(Conn). udiei. mytilus (Doflein). 



Family 2. EUPLOTIDAE. 



Cilia very little developed or absent; large bristles and spines char- 

 acterize the ventral surface; nucleus ribbon-shaped; body round or oval: 

 5 genera; mostly marine. 



Key to the genera of Euplotidae here described : 



Oi No posterior hook-like projection at side of body. 

 J)i Anterior bristles present. 



Ci About 9 anterior bristles 1. Euplotes 



Cn About G anterior bristles 2. Diopiirys 



&2 No anterior bristles 3. Uronychia 



Oo Posterior hook-like projection at side of body 4. Aspidisca 



1. Euplotes Ehrenberg. Body oval 

 or round, either green or colorless; mouth 

 in the hinder half of body, a long arched 

 oral groove joining it with the front end 

 of the body ; about 9 large bristles oppo- 

 site the groove and a similar number of ^ 

 anal bristles : 5 species ; in fresh and salt 

 water. 



Fig. 114 Fig. 115 



E. Charon (0. F. Miiller) (Fig. 114) . pj^ ^^^_j^ upiotes charon 



Lenofh 04.'S tutti • in frpsh qnd qnlf (Calkins). Fig. 115 — Diophrys 

 i.tn^in .u-io mm., in iiesn ana salt appendiculatus (Calkins). 



water. 



2. DiOPHEYS Dujardin. Like Euplotes except that about 6 anterior 

 and 8 anal bristles, all very long and thick, are present ; movement rapid 

 and continuous, not by jumps: 2 species; marine. 



D. appendiculatus Stein (Fig. 115). Length .05 mm.: Woods Hole. 



