Among Cladophora, in 8 to 13 fathoms on the south Bide of St. Ignaoe. 



Gammarus htcustris Smith, sp. imv. — Eyes slightly elongated, black. Antennuhe not 

 quite half as long as the body, and furnished with a few short hairs; first and second 

 segments of the peduncle equal in length, third much shorter; flagellum twice as long 

 as the peduncle. Antenna' a little shorter than the antennuhe; ultimate and penul- 

 timate segments of the peduncle equal iu length, the basal segments short; flagellum 

 considerably shorter than the peduncle. Guathipoda about equal in size; propodus in 

 the first pair elongated and much narrowed toward the articulation of the propodus, 

 palmary margin slightly concave, continuous with the posterior margin, and furnished, 

 like it, with several stout spines aud numerous long hairs ; dactylua slightly curved 

 and fully half as long as the propodus; propodus in the second pair a little broader, the 

 lateral margins nearly parallel, the palmary margin somewhat oblique, slightly concave, 

 and furnished with a thin raised margin and several stout spines, the posterior margin 

 without spines, but furnished with numerous fascicles of hairs. Pleon rounded above, 

 the fourth and fifth segments each with three fascicles of two or three small spines. 

 Third, fourth, and fifth pairs of pereiopoda subequal, their basa narrow and the margius 

 furnished with few minute spines. Kami of the posterior pair of pleopoda very slender, 

 the edges furnished with long hairs and a few spiues, inner only a little shorter thau 

 the outer. Length, 15 to 20 mm . 



Color in life, uniform, obscure dark-brownish green, without spots or markings of 

 any kind. 



Common in company with the last species in 8 to 13 fathoms; also, at Simmons's 

 Harbor, in 13 to 15 fathoms ; aud among the Slate Islands in 4 to 6 and 12 to 14 fathoms. 



Isopoda. 



Aselhts tenax Smith, sp. nov. — Head broad, with a large rounded sinus in the margin 

 on each side opposite the eye, back of which the margin projects in a rounded lobe, so 

 that the head is not narrower, posteriorly, than the anterior margin of the first segment 

 of the pereion. Eyes small, prominent, and separated from the margin of the head by 

 more than their diameters. Antennulae much shorter than the peduncles of the 

 antennae. Antenna? half as long as the body ; the flagellum longer than the peduncle. 

 Propodus in the first pair of guathipoda narrow and elongated, but considerably 

 stouter in the male than in the female ; dactylus more than half as long as the propodus 

 and its palmary edge armed with acute spines, of which the distal ones are larger. The 

 succeeding pairs of legs all similar, the carpal and propodal segments subequal in length 

 and armed with short spines along the posterior edges ; the dactyli short, armed with 

 a few spines on the posterior margin and bi-unguiculate at tip. Pleon narrowed pos- 

 teriorly, and the extremity obtusely rounded. Posterior pleopoda slender, the outer 

 ramus only half as long as the inner. Length, 8 to 13 mm . 



Color above dark fuscous, spotted and mottled with yellowish. 



Common with the last two species, among the Cladophora, in 8 to 13 fathoms on the 

 south side of St. Ignace, also in 4 to 6 fathoms at the eastern end of St. Ignace, and in 

 6 to 8 fathoms among the Slate Islands. 



Entomostraca. 



Numerous species of entomostraca were collected at different points, but this group 

 of crustacea has been so entirely neglected in this country that their investigation will 

 require much careful study, and I can notice them now only iua very general way. 



Of the Cladooera, species of Daphnia and Lynceus were abundant among the Cladophora 

 on the south side of St. Iguace. A species of Daphnia, different from the one just 

 mentioned, and a species of a closely allied genus, were taken by towing the dredge a 

 short distance below the surface. These species Avere also once or twice brought up in 

 dredging in deep water, perhaps taken in the dredge on its way up. 



Ostracoda of several genera and quite a number of species were collected, some of 

 them being found in nearly every dredging, even down to 159 fathoms. 



Of Copepoda, species were obtained at nearly every haul, some of them the same 

 species as those obtained near the surface, but many of them different, and undoubtedly 

 from near the bottom. They were almost always abundant in the dredgings in which 

 Mysis occurred, undoubtedly furnishing most of its food. 



ANNELIDA, (Worms.) 

 Lumbricid^e, (Earth-worms, &c.) 



Lumbricus lacustris Verrill, sp. nov. — About 1.5 inches long, .04 in diameter. Body 

 round ; distinctly auuulated. Head short, conical, obtusely pointed. Setae spine-like, 

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

 reddish brown. 



South side of St. Ignace, among Cladophora, 8 to 13 fathoms, abundant. 



