1890.] An American Terrestrial Leech: ~ 647 
This terrestrial leech was first obtained by me in April, 1876, 
at Normal, McLean county, Illinois, where it was dug up ina 
house garden about a dozen rods from the nearest rivulet. An 
example sent the following year to Prof. A. E. Verrill, with some 
remarks on its superficial characters, was by him identified, provis- 
ionally and with some hesitation, as his Semzscolex grandis, orig- 
inally described! from three aquatic individuals obtained from 
Lake Huron and Lake Superior and a river in Connecticut. I 
have now, however, fifty-six specimens of this leech, all from the 
earth in central Illinois, sometimes half a mile or more from 
water, and representing collections made at different times from 
April, 1876, to June, 1890; while, on the other hand, it has not 
once occurred in the course of a large amount of aquatic work 
done in the same regions during these fifteen years. It has, 
moreover, constant characters which clearly distinguish it from 
Semiscolex grandis, as far as one may judge by a comparison 
with Verrill’s description, and I do not doubt that it is unde- 
scribed. Its only known food is earthworms of various genera, and 
these it swallows entire—as I have repeatedly found by dissec- 
tion, and demonstrated likewise by feeding experiments on leeches 
in captivity. Indeed, my serial sections have this peculiarity : 
that they present the structure of three worms in one section— 
that of the leech itself and of two earthworms in its stomach. 
From the fact that all my specimens were obtained during the 
early months of the year—from March to June—it is probable 
that this leech, like the earthworm, penetrates to considerable 
depths during the midsummer drouths. 
Diacnosis: Semiscoler terrestris, n. sp. This is one of the 
largest of our leeches, my contracted alcoholic specimens reaching 
a length of seven inches, a width of three-fourths, and a depth of 
three-eighths of an inch. In form, it is heaviest posteriorly, be- 
1 Synopsis of the North American Fresh-Water Leeches. By A. E. Verrill. U. S. 
Commission of Fish and Fisheries. Part II. Report of the Commissioner for 1872 and 
1873, p.672 (Published in 1874.) This species clearly belongs to Kinberg's genus Semis- 
colex, but on the other hand there seems little, except the very rudimentary condition of 
the pharyngeal jaws, to ve it from Aulastoma, Moqu. (See Diesing, Systema Hel- 
minthum, Vol. I., p. 461; Apathy, Süsswasser-Hirudineen, in Zoologische Jahrbücher, 
Band III., p. 793), but in = absence of material for a comparison of these genera, I have 
followed Verrill in using Kinberg's name. 
Am. Nat.—July.—4. 
