INVERTEBRATE FAUNA OF LAKE SUPERIOR. 697 



even down to 159 fathoms. They were more abundant, however, in 

 shallow water, and were especially numerous in 8 to 13 fathoms, among 

 Cladopliora, on the south side of Saint Ignace Island. 



COPEPODA. 



Several species of Gopepoda were often very abundant at the surface 

 of the water, while I was on the lake, and large numbers were collected. 

 Species were also brought up in the dredge at almost every haul, most 

 of them the same species as those obtained near the surface, but some 

 were different and undoubtedly from near the bottom. They were almost 

 always abundant in the dredgings in which Mysis occurred, apparently 

 furnishing most of its food. 



SIPHONOSTOMA. 



Lern^opoda siscowet Smith, (p. GGl.) 

 Lern^opoda (?) Coregoni Smith, (p. 664.) 



WORMS. 



OLIGOCH^TA. 



LuMBRicus LACUSTRis Yerrill. 



American Journal of Science, 3d series, vol. ii, p. 449, 1871 ; and Preliminary 



Report on Dredging in Lake Superior, p. 1023, 1871. 



About 42™°» long, 1°^°^ in diameter. Body round, distinctly annulated. 



Head short, conical, obtusely pointed. Setce spine-like, strongly curved, 



acute, arranged two by two, those of each pair close together. Color 



reddish brown. 



Abundant, in 8 to 13 fathoms, among Cladopliora, on the south side 

 of Saint Ignace Island; also from the stomachs of white fish taken at 

 Outer Island. 



S^NURiS ABYSSICOLA Verrill. 



American Journal of Science, 3d series, vol. ii, p, 449, 1871 ; and Preliminary 

 Report on Dredging in lake Superior, p. 1024, 1871. 

 Worm slender, attenuated posteriorly, about 7™'".5 long, 0'""'.75 in 

 diameter anteriorly. Body composed of about twenty-eight segments ; 

 those of the posterior half elongated ; those of the anterior half shorter, 

 separated by slight constrictions. Cephalic lobe short, subconical, 

 rounded i)i front. Mouth large, semicircular. Intestine slender, monili- 

 form, containing sand. Anus terminal, with three or four slight lobes. 

 Setae in four fan-shaped fascicles on each segment, commencing at the 

 second segment behind the mouth. The two ventral fascicles are sepa- 

 rated by a space equal to about twice the length of the set<e, of which 

 there are five or six in each fascicle; the setae are simple, acute, slightly 

 curved, equal to about one-sixth the diameter of the body. The lateral 



