Ko. 482] SOUTH AMERICAN ROTIFERS 



99 



but the arrangement of the spines shows that it belongs t 

 species. This variety is also found in India and Africa. 



(Fig. 



-Long ante- 

 rior spines few, usually 4 on 

 each side, the 2d and 4th of 

 these much thicker than the 

 others. The lateral spine of 

 the anterior row on the central 

 segments of the trunk large 

 and very thick. Skin strongly 

 stippled or papillose. 



Other smaller differences 

 from the type will be better 

 understood from the figure. 

 There was no variation from 

 this arrangement of spines in 

 all the examples seen. The 

 variety is much smaller than 

 the type. About 6 examples 



Specific characters. — Small, 240 n long, hyaline or whitish, 

 with pale yellow stomach, food not moulded into pellets. Head 

 small, corona 40 wide, less than collar and about half diameter 

 of central trunk, discs touching, central process of upper Hp 

 single, truncate. Length of antenna \ diameter of neck. Jaws 

 18 /( long, teeth '2 1\ veiy thin. Foot 4-jointed, spurs narrow, taper- 

 ing, divergent; toes large and long, the two ventral put out and 

 drawn in. in the u>ual manner, wIhmi making the step, the dorsal 

 kept alway> extende.l an. I fornn-ng with tin- ^purs a tripod. Dorsal 

 skin Folds faint, few. lafral deeper. The striking peculiarity is 

 the tripod, whi.'h i> um'<|ue in the order. ( )therwis<> the animal 

 comes nearest ('. r/urnhrnj; .lanson. from which it is .li.tinguished 

 by the smaller head, closer discs, and tnmcate upper hp. Abun- 

 dant. 



