NOV 15 1897 



New Species of Hotifh'a and Protozoa. 311 



a deep sinus on each side. The surface of the lorica is 

 marked by short ridges running back from the spines 

 and median processes. 



The posterior spines are about one fifth the length Oi 

 the lorica. In many specimens, especially old ones, 

 these spines are quite short, and in some instances the^v 

 are entirely wanting. So far as observed, the newly 

 hatched young and embryos in the eggs all possess the 

 posterior spines, this indicating that the spines are 

 characteristic of the species and are shed or absorbed 

 only in old age. The quadrate plate over the foot 

 orifice may serve as an easy means of identification, 

 since I know of no other member of this genus that 

 has a similar structure. The eggs are carried about fast- 

 ened to the posterior part of the lorica. 



The internal structure of this rotifer is normal. There 

 is a large subquadrate dark-ruby e3^e just in front of 

 the mastax. The foot and two toes are small for such 

 a large species. Length of lorica, including spines, .812 

 mm. to .418 mm.; width .209 mm. to .257 mm. 



This species was found in tows from the Illinois River 

 Quiver Lake, Thompson's Lake, and Phelps Lake. It 

 is very restless and active, and occurs only in open 

 water, free from vegetation. 



BracJiionus pwictatus n. sp. 



(Plate XXIII., Fig. 3-5.) 



Lorica, as seen dorsally, subquadrate, sides slightly 

 convex. A cross section would be nearly circular. 

 Four occipital spines of about equal length, curv. 

 ing slightly downward and outward. In the lumbar 

 region there is a slight invagination of the lorica on 

 each side, thus causing blunt angles on the surface of 

 the lorica, and making it irregular. The entire suiface 

 and spines are covered with minute spinules. The surface 

 of the lorica is also marked off into areas by several 

 curved lines. There are no posterior spines. 



