120 THE LEECHES OF MINNESOTA 



Habits — This great leech is found on the shores of the Great 

 Lakes and abounds in the numerous lakes and ponds of Wisconsin, 

 Minnesota and Michigan. Eastwardly it extends its range through 

 New York into New England but is rare in the Middle States and I 

 have had but little opportunity to study its habits under natural con- 

 ditions. 



It appears to live chiefly about the borders of the bodies of water 

 which it affects, concealing itself beneath stones. According to Bar- 

 rows it secretes an unusual abundance of mucous and I suspect from 

 this fact and the large size of the nephridial bladders that it may upon 

 occasion leave the water. Stomach examinations show that its food 

 consists of earthworms and allied aquatic worms, smaller leeches, 

 particularly the nephelids, snails, insect larva? and organic mud. In 

 captivity several individuals fed voraciously on earthworms but could 

 not be induced to attack fishes, frogs or turtles even when the skin was 

 abraded so that the blood flowed, from which behavior it would appear 

 that the accounts of this species habitually attacking fish require to be 

 verified. 



Family Herpobdellidae. 



Leeches of mostly moderate size and slender elongated form, usu- 

 ally terete anteriorly, often much depressed posteriorly. Clitellum as 

 in Hirudinidae. Oral sucker small, forming lips ; caudal sucker also 

 small, discoid. Complete somites fundamentally of five rings, but one 

 or more often subdivided, forming six to eleven rings. Eyes usually 

 four pairs, two pairs on somite II often coalesced, two pairs of smaller 

 size on IV; but sometimes eyeless. Cutaneous sense organs and papil- 

 lae numerous, not obviously metameric. Mouth and pharynx as in 

 Hirudinidce, but the latter with three longitudinal muscular ridges and 

 no jaws. Stomach and intestine straight, simple and without divertic- 

 ula. Genital orifices variable in position, the male usually on XII, the fe- 

 male on XIII. Testes sacs small and very numerous, extending through 

 about segments XVIII to XXIII. Sperm ducts very long and much 

 eonvoluted, paired until they empty by means of the short prostate 

 cornua into the small median atrium. No protrusible penis. Ovisacs 

 long and slender as in Glossiplioiiidce but each doubled on itself, 

 united only at the external orifice. Copulation takes place and 

 spermatophores are implanted on the integument. Eggs enclosed in 

 Hat, pouch-like chitinoid cocoons fastened by one side to stones, sticks, 

 plants, etc. Fresh water predaceous leeches, feeding on insect larva?, 

 worms, etc., occasionally suck the blood of vertebrates. 



