THE LEECHES OE MINNESOTA 83 



being- situated at XI/XII, the female XII 02/(13. The vasa defer- 

 entia have the customary long posterior loops and enlarged sperm 

 sacs. A very remarkable feature and one that is peculiar to this 

 and a few very closely allied species is the presence of nine or ten 

 pairs of testes in place of the six pairs usually present. The addi- 

 tional pairs are added at the caudal end of the series in somites XX 

 to XXIII. 



A more or less obvious narrowly striped pattern results from 

 the more superficial pigments showing through the rather opaque 

 integuments along the lines of the longitudinal muscles. The gen- 

 eral effect is a somewhat heavy green or brown ground color 

 marked dorsally and ventrally by a pair of very conspicuous longi- 

 tudinal brown lines which above begin just behind the eyes while 

 below they are slightly farther apart. The dorsal lines are broken 

 into a series of short dashes by small metameric white or sulphur 

 yellow spots corresponding with the dorso-medial papillae on the 

 neural annuli. Four or five additional series of similar spots occur 

 on the neural annuli, making six or seven in all. Of these the 

 median series is the least constant, the others including the four 

 constant papillae, to which two marginal series must be added. 



Habits — The snail leech, as this species is named in England, 

 abounds in certain localities in the shallows of rivers and large 

 ponds, where it is found concealed beneath stones. It is remarkable 

 among the small glossiphonids for its great muscular strength, 

 which enables it to overcome its prey and to adhere to stones with 

 great tenacity. While more tardy in seeking to escape when dis- 

 turbed than its most usual associate, G. stagnalis, it is more active 

 in its movements when once aroused. It is more prone than most 

 species to roll into a ball and may remain quiescent in this condi- 

 tion for a considerable period. 



Although occasionally found attached to turtles the snail leech 

 has not been observed to suck blood, but so far as my observations 

 extend feeds exclusively in its natural habitat on small snails, worms 

 etc., which its strength enable it to quickly overcome. 



As usual the eggs are carried on the ventral side of the body 

 and their large. number, as well as the great length of the breeding 

 season, render this one of the most satisfactory species for embryo- 

 logical study. It is one of the earliest as well as one of the latest 

 of the Glossiphonias to bear eggs, which are contained in a small 

 number of unusually large capsules. 



