8_> THE LEECHES OF MINNESOTA 



Glossiphonia complanata (Linnaeus) Johnston. 



(Plate I, fig. 4) 



Hirndo complanata Linnaeus (1758) 

 Clepsine clcgans Yerrill (1874) 



Description — Although not much exceeding the species previ- 

 ously described in length when extended this leech is considerably 

 larger and more bulky than any of them. The body is rather broad 

 and flat with thicker margins, though G. fusca approaches it in this 

 respect, and like that species it is incapable of great extension. In 

 this connection it is interesting' to note that both of these species 

 have remarkably well developed longitudinal muscles. The head 

 is not distinctly widened and the posterior sucker is small but pow- 

 erful and less strongly directed ventrad than in the large species of 

 Placobdclla. There are at least four series of low, rounded but 

 rather large cutaneous papillae on which the dorso-median and 

 dorso-lateral sensillae are borne. There is no median series. 

 Numerous small sense organs roughen the integument, which is 

 rather opaque. A character which is quite unique among the 

 Glossiphonidcc herein described is the presence of three distinct 

 pairs of eyes situated on somites II, III and IV respectively. They 

 are close together near the middle line and the pigment cups of the 

 first are sometimes in contact, while the second are farthest apart 

 and the largest in size. There is no nuchal gland. 



Somites I and II are uniannulate, sometimes indistinctly sep- 

 arated; III is uniannulate or indistinctly biannulate ; IV is biannu- 

 late, divided by a rather faint furrow into a larger anterior and a 

 smaller posterior annulus. The next somite (V) is biannulate or 

 more usually triannulate by the separation of ar by a shallow fur- 

 row from a?. Somites VI to XXIV "inclusive are fully triannulate; 

 XXV is biannulate and XXVI and XXVII usually uniannulate, 

 the former frequently exhibiting some marginal division. 



The mouth is of relatively large size and placed at the boundary 

 between the second and the third somites. Like the closely related 

 species the salivary glands are diffuse. Six or seven pairs of simple 

 or slightly branched gastric cneca are present, the last reflected but 

 relatively shorter than in the blood-sucking species of Placobdclla. 

 The longitudinal muscles of this species are remarkably powerful. 



Unlike the three species of Glossiphonia described above the 

 genital orifices of this species are separated by two annuli, the male 



