206 M. M. Mercaur 
fered to cold fluid of the same sort. The heat is valuable since it 
makes caagulation instantaneous and the objects hold firmly to the 
cover-glass upon which they are spread. 
O Cine ) 0 
satutnalis — untestinalis CAUdAKE macronucteata 
a ike 
FP (> Qo ¢ 
lanceclaia, damidiata zellerr longa 
0° 0- O= 
flava Lata TANaAtUM 
ies Cpe 
coracardea ObLLLQONG 
Textfig. II. Outline drawings of surface views and cross sections of the known 
species of Opalina. The nuclei are indicated only for those forms that have few 
nuclei. The relative size of the different species is not shown. In each case the 
anterior end is above and the bend of the anterior end of the longitudinal axis is 
toward the right. 
