The Hirudinea of Illinois. 535 



Habits. — The favorite food of this species is small aquatic 

 oligochgetes. Bristol ('98) and Leidy ('70) have given some 

 account of its habits. 



DiNA R. Blanchard. 

 Dina fervida (Verrill). 



Nephelis fervida Verrill ('74). 



Nephelis fervida is supposed to have been described from 

 individuals of this species having eight eyes, a variation 

 which frequently occurs. The species here described is 

 abundant in the Lake region from which Verrill's types were 

 taken, and has the size, form, and color of that species. 



Diagnosis. — Complet esomites quinqueannulate, b 6 being 

 distinctly enlarged and divided by a cross-furrow into two 

 equal halves ; pigmented eyes normally three pairs, the first 

 situated on III ; genital orifices at XII b 2/a 2 and XII b 5/b 6 ; 

 median chamber of atrium of medium size and not deeply 

 cleft, the prostate cornua prominent, and the vasa deferentia 

 not reaching anterior to their ends in somite XII. 



General Description. — A single small specimen represents 

 this species in the Illinois collections, and the following notes 

 are derived from numerous examples in my own collection 

 received from Ohio and Michigan and from the well-preserved 

 series taken by Professor Reighard during his recent explo- 

 ration of Lake Erie. 



None of the large number of specimens examined reaches 

 a length of much more than two inches. The body is 

 depressed posteriorly ; the mouth is relatively large and the 

 lip blunt. The posterior sucker is relatively larger ihan in 

 most small nephelids, with its anterior margin more broadly 

 free and reaching as far forward as XXV a 2. The body is 

 not of particularly firm consistency. The clitellum extends 

 over fifteen annuli, X b 5 to XIII a 2. 



The annulation and metamerism are essentially as in 

 E. punctata, except that the first pair of eyes is placed on 

 the third instead of the second annulus, and that in the com- 



