958 ZOOLOGY LEECHES. 



AULASTOMUM LACUSTRE Leidy. 



Aulastomwn lacmtrc LEIDY, Proc. Acad. Nat. Sci. Phil., 1868, 229. VEREILL, Am. 

 Jour. Sci., iii, 1872, 135. Id., Syn. N. A. Fresh Water Leeches, iii Report U. 

 S. Com. Fish & Fisheries, 1874, G70. 



This species, as described by Dr. Leidy, has ten ocelli, eight in the 

 upper lip ; the last pair separated by an annulus from the others. Male 

 aperture in the twenty-fourth annulus ; female orifice in the twenty-ninth. 

 (Esophagus capacious, with twelve folds. "Jaws thin, small, when at rest 

 included in pouches formed by an eversion of the mucous membrane. 

 Teeth, twelve in number to each jaw, bilobed at base." Color (var. a) 

 throughout olive-green, closely maculated everywhere with confluent spots 

 of a darker hue of the same color. When full grown, this species becomes 

 six to eight inches or more long and half an inch broad. 



In my specimens, the male organ is long, very slender, thread-like, and 

 is protruded from an opening in the twenty-fifth segment behind the mouth 

 (counting the buccal segment). The female orifice is small, with slightly 

 raised borders, and is situated between the twenty-ninth and thirtieth seg- 

 ments. The fourth pair of ocelli is on the buccal segment ; and the fifth 

 pair is on the third segment, behind the mouth. 



Var. 1), tigris. Large and broad, depressed. Color yellowish-green to 

 dark olive-green, with scattered irregular blackish spots and blotches. 



Var. c, fuliginosum. Color uniform dusky or brownish-black. 



Var. d, virescens. Color uniform greenish or yellowish-green, varying 

 to dark green ; usually paler beneath. 



Connecticut to Lake Superior, Utah, and New Mexico. 



Var. a, Denver, Col., H. W. Henshaw, expedition of 1873 ; August, 

 1873, between Santa Fe and Fort Wingate, N. Mex., Dr. Oscar Loew. 



Var. I, Fail-field, Utah, Dr. H. C. Yarrow ; in a tributary of Great Salt 

 Lake, Utah, 1872; Taos, N. Mex., 154 B, Dr. II. C. Yarrow, 1874. 



NEPHELOPSIS OBSCURA Verrill. 



Nfpkelopsis obscura VEKRILL, Am. Jour. Sci., iii, 135, 1872. Id., Syu. N. A. Fresh 

 Water Leeches, in Rep. U. S. Com. Fish & Fisheries, 1874, 674. 



Body much elongated in extension, depressed posteriorly, distinctly 

 amralated, a little rugo.se anteriorly in contraction. Length, in extension, 

 4 to 5 inches; breadth, 0.25 to 0.35 of an inch. Head obtusely rounded 



