88 THE LEECHES OF MINNESOTA 



semblc in form and mode of fixation. The eggs are very numerous 

 and are fixed lightly to the ventral surface of the body covered by 

 a delicate mucoid membrane. During the period of incubation the 

 parent leech attaches itself firmly and is very loath to leave its 

 resting place. If, under such circumstances, force be used the 

 leech holds tenaciously by both suckers to its support and curls 

 the lateral margins of the body in such a manner as to enclose the 

 eggs or young. As a result of a struggle to remove the brooding 

 leech the eggs are generally detached and are then sometimes found 

 to be adherant to the stone or glass of the aquarium against which 

 they have been pressed. When forcibly removed from the eggs the 

 leech will usually seek and return to them. 



Placobdella montifera nom. nov. 



(Plate I, fig. 5, Plate II, fig. 10) 



Clepsine papillifera var. carinata Verrill (1874) 

 Not Clepsine carinata Diesing (1858) 

 Hciniclcpsis carinata Moore (1901) 



Description — The size is moderate, never approaching the 

 maximum of the two species of the genus already described. In 

 addition to the widely expanded discoid head, which is quite char- 

 acteristic, the form is more slender and less flattened and foliacious 

 than usual in the genus. The posterior sucker is large, circular, 

 rather freely pedicillate and minutely denticulated about the mar- 

 gins. The oral sucker also possesses unusual mobility, has a promi- 

 nent free margin all around and a narrow unsegmented border. The 

 capacity for extension and contraction exceeds that of either P. 

 parasitica or P. rugosa. The dorsum bears three rows of very large 

 conical papillae situated on the second and third annuli of each 

 somite for the greater part of the body as far as somite XXI. These 

 are borne on the crests of three prominent nearly continuous ridges. 

 On somites XXII to XXVI the three tuberculated keels cease and 

 are replaced by a pair of large paramedian papillae on each somite. 



The anterior somites are better developed than in the closely 

 related species, no doubt in correlation to the formation of the 

 distinct head, into which the first five enter. The first two are each 

 faintly biannulate, III is distinctly biannulate, with ai obscurely sepa- 

 rated as a small anterior ring, behind which is situated the pair of small 

 eyes. There are seventeen completely triannulate somites (VI to 



