90 



THE LEECHES OF MINNESOTA 



Although Verrill was the first to describe this species, his 

 name, which I used in a former connection when the species was 

 erroneously referred to Hemiclepsis, is preoccupied by Clcpsine ' 

 carinata Diesing (1858) which is unquestionably a Placobdclla. 

 The name montifera is therefore proposed as suggestive of the resem- 

 blance of the carinie to conventional mountain ranges. 



Placobdella Pediculata Hemingway. 



Plate II, Figs. 13-18. 



Placobdella pediculata Hemingway, American Naturalist, Vol. 

 XLII, 1908, pp. 527-532, figs. 1-3. 



Description* — Like Placobdella parasitica and P. ritgosa this 

 species reaches a large size, though no specimens quite equal- 

 ling the largest examples of these, its allies, have been seen. 

 Judged by the poor state of preservation of the few adults that I 

 have examined it is in life soft-bodied and more than usually 

 contractile. All of these specimens — numbering six — are gorged 

 with blood and in this state are thick and hard in the region of 

 the body occupied by the gastric cseca. All are strongly con- 

 tracted and have the very characteristic pyriform outline and 

 strongly convex dorsum evident in the figures, but the most strik- 

 ing peculiarity is the abrupt contraction and attenuation of the 

 posterior segments to form a narrow pedicle supporting the cau- 

 dal sucker, which, consequently, stands out freely exposed be- 

 hind the wide posterior part of the body in a most characteris- 

 tic manner. Hemingway has made the interesting discovery that 

 this condition arises in the course of individual development and 

 does not exist in young leeches one centimeter long, which con- 

 sequently differ less obviously than do the adults from related 

 members of the genus. The oral sucker, as far as can be de- 

 termined in its contracted state with the lip inrolled, has the same 

 structure as in P. parasitica. 



The skin is perfectly smooth, without a trace of cutaneous 

 papillae; and only a few obscure segmental sensilkx and Bayer's 

 scattered sense organs, the latter chief! v near the margins of the 



"This description is printed substantially ;is originally prepared for 

 tin's report bul several important additions and corrections, for which I am 

 indebted to Hemingway's paper, are either bracketed or specifically cred- 

 ited to that source. 



