6 



length, of an obscure liver-brown color, was taken in G to 9 fathoms, among the 

 ■Slate Islands, which probably belongs t" this species. 



Ickthyobdella punctata Verrill, sp. nov. — Body, in extension Blender; in the preserved 

 specimen, about .5 of an inch long, .oti in greatest diameter, rounded, thickest poste- 

 riorly, tapering anteriorly to the anterior sucker, which is broad and thin, snbeireiilar, 

 about three times as wide as the neck where it is attached ; ocelli four, on the upper 

 side of the anterior sucker, the two larger, black ones, in front, and two minute ones 

 wider apart and farther back. Posterior sucker large, rounded, or oval. Color trans- 

 lucent greenish, with minute black specks, arranged in transverse bands. 



Among the Slate Islands, G to 8 fathoms. 



c", c. DENDROCCELA , (Flat-worms.) 



Procotyla fluviatilis Leidy. — Numerous specimens, apparently of this species, were 

 obtained in 8 to 13 fathoms, on the south side of St. Ignace. They were, when living, 

 dirty white, mottled with brown. 



In addition to the preceding species of worms, a few were obtained which have not 

 yet been fully determined. 



MOLLUSC A. 

 Gasteripoda. 



Limnfyy. — A species allied to L. disidiosa Say, was abundant among Cladophora in 8 

 to 13 fathoms, on the south side of St. Ignace Island. 



Physa het&rostroplia Say. In the cove at the eastern end of St. Ignace, in 4 to 6 fath- 

 oms, and young specimens in 8 to 13 fathoms, at the locality with the Limnwa just 

 mentioned. 



Physa vinosa Gould. — A very young specimen, apparently of this species, in 6 to 8 

 fathoms, among the Slate Islands. 



Planorbis parvus Say. — Common in 8 to 13 fathoms, on the south side of St. Ignace. 



Valvata sincera Say, sp. — Abundant with the last species, in 8 to 13 fathoms, and 

 also in 4 to 6 fathoms, in the cove at the eastern end of the same island. 



Lamellibranchiata. 



Sphcerium, sp. nov. f Among the Slate Islands, in 6 to 8 fathoms. 



A single young specimen of another species of Sphcerium was found, in 8 to 13 fath- 

 oms, on the south side of St. Ignace. 



Pisidium Virginicum Bourguignat. On the south side of St. Ignace, 8 to 13 

 fathoms. 



Pisidium ahdihnn Haldemah. With the last species, in 8 to 13 fathoms, and also in 

 4 to 6 fathoms, in the cove at the eastern end of the same island. 



Pisidium compression Prime. In the cove at the eastern end of St. Ignace, 4 to 6 

 fathoms. 



Pisidium, sp. nov. A small, semitranslucent species, the same as found by Dr. Stimp- 

 son in Lake Michigan, was brought up at nearly every dredging. It was common in 

 the cove at the eastern end of St. Ignace, on sandy and muddy bottom, in 4 to 6 

 fathoms, and abundant among Cladophora, in 8 to 13 fathoms, on the south side of that 

 island ; among the Slate Islands, in 6 to 8 and 12 to 14 fathoms ; at 13 to 15 fathoms 

 on a sandy bottom in Simmons's Harbor ; uear Copper Harbor, in 17 fathoms, clear 

 sand ; in 32 fathoms, very soft clayey mud, in Neepigon Bay ; oti' Copper Harbor, in 

 62 fathoms, and north of Keweenaw Point, in 82 fathoms, soft reddish clayey mud and 

 sand ; and in all the deep dredgings down to 159 fathoms. Below 100 fathoms, how- 

 ever, it was never abundant. 



RADIATA. 



Hydra carnea Agassiz. A beautiful Hydra, agreeing with Ayer's description of this 

 species, was very abundant at the eastern end of St. Ignace, upon rocks along the 

 shore and near the surface, frequently completely covering quite large surfaces, where 

 they were protected from the direct sunlight, and was also brought up in many of the 

 dredgings from 8 to 148 fathoms. In 32 fathoms, Neepigon Bay, and in 59 fathoms 

 otf Simmons's Harbor, it was brought up in abundance from a soft clayey bottom. In 

 the deep dredgings, it frequently came up near the bottom of the clay in the dredge, 

 and was evidently not caught while the dredge was near the surface. 



A noticable feature of this imperfect faunal list is the remarkable development of 

 the Lumbricida', or the family of earth-worms, which is represented by six aquatic 

 species, all but one of them being inhabitants of deep water. 



As regards the geographical distribution of species, the most important fact elicited 

 is, undoubtedly, the identity of the species of My sis and Pontoporeia with- those of the 

 lakes of Northern Europe. 



