I 



OF DENISON UNIVERSITY. '47 



Floscularia ornata, Ehr. 



is not a rare inhabitant of the pools of Minnesota. The very full de- 

 scriptions of this species, given by various authors, would seem to have 

 exhausted the subject, but we do not even yet feel sure that the so- 

 called species are not local or age variations. The other species are 

 F. appendictdata^ F. proboscidea^ F. complanata^ F. longiloba, and F. 

 trifolium. 



Of Rotifer and Callidina we find a number of species, but reserve 

 the consideration of the group for another occasion. 



Notojnjnata furnishes several species which are very abundant and 

 striking, but a large number of works are necessary for their study. 



GENUS EUCHLANIS, Ehr. 



The lorica is oval and composed of an arched dorsal shield and a plane ven- 

 tral one. The lorica in front is broad and presents a large opening for the head. 

 The shell often has a carina above, while the dorsal shield is movable upon the 

 ventral. The trochal disc is strongly ciliate and bears two terminal sensory or- 

 gans with clumps of tactile hairs. There is a single cervical eye and the viscera 

 are highly differentiated. The foot has four short segments and two terminal 

 lanceolate claws. 



EucHLANis (dilatata) hipposideros, Gossc. 

 {Plate III, Fig. 2.] 



The identification of our species with the above is made in spite of 

 minor points of disagreement which may be looked upon as the result 

 of faults in the descriptions or slight variations in structure. Eckstein 

 gives the length at .45 mm., while Eyferth says .23 mm. Our spe- 

 cies varies only between .22 and .24 mm. and is quite uniform, so far 

 as observed. The form is oval, the lorica being excavated before and 

 behind, as shown in the figure, although it is not often seen as clearly 

 as drawn. 



The trochal disc has two broken circlets of cilia, and on either side 

 the head is a pit densely ciliated within. The drawing given by Eck- 

 stein shows the arrangement well. Two curious sensory organs oc- 

 cupy the very front of the head. The ganglion is very large and 

 quadrate, the eye being near its anterior part and quite large. The 

 maxtax is quadrate, showing the component parts well. The stomach 

 is ob-pyriform and there are two accessory glands. The ovary has 

 very large nuclei and the egg is of great size. The contractile vessel 



