NORTH AMERICAN FRESH-WATER LEECHES. 669 



face briglit or dark orange-red, or reddish brown, sometimes with bhxck 

 spots near the margins. 



This species is very common, and widely diffused in the fresh waters 

 of the iSTorthern United States. Its range northward and southward is 

 unknown. It is the only true blood-sucking leech known to me from 

 the iforthern States. It is capable of drawing blood from the human 

 skin, but ordinarily subsists upon fishes, frogs, and tadpoles. It often 

 attaches itself to the throat, and speedily kills them, even when of con- 

 siderable size. It is frequently used instead of the imported leeches by 

 physicians, and is equally efficacious, 



Vermilion River — Say; Norway, Me.; in many lakes and streams in 

 other parts of Maine; and in streams and ponds near New Haven — A. 

 E. Verrill ; Minnesota — Dr. Leidy ; Madeline Island, Lake Superior — 

 J. W. Miluer; Smoky River, Kansas — 0. Harger. 



Subgenus Philobdblla Verrill. 

 The remarkable characters of the reproductive organs in the following 

 species entitle it to at least subgeneric rank. The jaws also differ con- 

 siderably from those of the preceding species, and it may be liereafter 

 necessary to make it a distinct genus. 



Macrobdella Floridana Verrill, sp. nov. 



Body much depressed, except near the head ; in preserved specimens 

 about 1.5 inches long and 0,28 of an inch wide. Ocelli, ten, small; the 

 first two pairs are near together, on the front of head, apparently on the 

 first segment; the third pair is on the second segment; the fourth is on 

 the fourth ; and the fifth pair is on the seventh segment, or fourth poste- 

 rior to the mouth. The anterior lip is, in the preserved specimens, 

 short, broadly rounded, and incurved ; the lower surface longitudinally 

 sulcated, with a thin, elevated, transverse fold posteriorly, in advance of 

 the jaws, behind which they can be retracted. Jaws, or maxillte, small, 

 but prominent, about as thick as broad, scarcely compressed, except 

 close to the blunt edge, which is armed with about twenty acute teeth, 

 ffisophagus with nine distinct folds, some of which are occasionally i^ar- 

 tially divided posteriorly^ Acetabulum rather small. In ordinary spec- 

 imens, the visible external reproductive organs consist of a small orifice 

 (male ?) between the twenty -eighth and twenty-ninth segments ; and an 

 elevated conical papiUa (female ?) arising from the twenty-ninth and 

 thirtieth segments, and followed by about three pit like depressions. 

 But two specimens, taken and preserved while in coitu, have an entirely 

 different appearance. In these, there is a large orifice, probably the 

 true male opening, apparently in the twenty-eighth segment behind the 

 mouth. Just in front of this, on the twenty-sixth and twenty-seventh 

 segments, there are two small lunate, median pits or openings, with 

 raised borders; and just behind it, on the twenty-ninth segment, there 

 is a larger transversely-bilobed orifice, or deep pit. These four open- 

 ings are surrounded by a raised area, somewhat circular in form, on 



