236 TROCHELMINTHES 



Key to the families of Illoricata here described: 



GX No foot present ; animals transparent, short and more or less spherical. 

 &! Animals spherical with a ring of cilia near equator .... 1. TEOCHOSPH^EIDAE 

 ft. Body sac-shaped. 



<?! No long lateral appendages 2. ASPLANCHNIDAE 



c a Long lateral appendages present with which the animal jumps. 



3. TBIABTHBIDAE 



2 Foot with 2 toes present. 



Z>! Corona with 3 to 7 large prominences with setae 4. HYDATINIDAE 



6 a Corona without these ; body elongate, often with a pair of ciliated pro- 

 jections ( auricles) 5. NOTOMMATIDAE 



FAMILY 1. TROCHOSPH^ERIDAE. 



Spherical rotifers without corona or foot and with an encircling 

 band of cilia near the equator or towards the forward pole; mouth 

 ventral and anus at the hinder pole; the viscera are in the hinder hemi- 

 sphere: 1 genus. 



TROCHOSPHJERA Semper. With the characters of the family : about 



3 species. 



T. solstitialis Thrope (Fig. 376). Band of cilia between equator 

 and forward pole ; diameter 2 mm. : in the Illinois River and at Put-in-Bay, 

 Lake Erie; Asia. 



FAMILY 2. ASPLANCHNIDAE. 



Large transparent sac-shaped rotifers, without anus and usually 

 pelagic: 3 genera. 



1. ASPLANCHNA Gosse. Foot absent; jaws large; animals vivipa- 



Fig. 377 Fig. 378 



Fig. 376 Trochosphcera solstitialis (Delage et He>ouard). 1, brain; 2, mouth; 

 3, kidney tubule ; 4, anus ; 5, intestine ; 6, ovary ; 7, dorsal nerve. Fig. 377 

 Asplanchna herricki (from Stissw. F. Deut.). Fig. 378 Polyarthra platyptera (from 

 Siissw. F. Deut.). 



rous, the embryo being frequently seen in the mother; 1 or 3 eyes present; 

 corona with two slight elevations: about 7 species. 



A. priodonta Gosse. Body without humps and barrel-shaped; eyes 

 3; length .5 mm.: often very common; pelagic. 



A. herricki* De Guerne (Fig. 377). Body amphora-shaped and 

 without humps; eyes 3: pelagic. 



* See "Early Development of Asplanchna herrickii," by H. S. Jennings, Bull. 

 Mus. Comp. Zool., Vol. 30, 1896. 



