NO. iroi. N0RTJTWE8T PACIFIC ISOPODS— RICHARDSON. 101 



small tubercles on the middle of the dorsal surface, one on either 

 side of the median line. At the base of the segment there is a prom- 

 inent lateral tooth or projection on either side. 



The first four pairs of legs are furnished with long hairs and are 

 anteriorly directed; the last three pairs are ambulatory. There are 

 four pairs of marsupial plates. (The female is described and figured.) 



A large number of specimens come from station 4982, on the way 

 from Hakodate, Hokkaido, Japan, to Otaru, Hokkaido, Japan, by 

 the Tsugaru Strait, at Benkei Mizaki Light, S. 3° E., 10.5 miles (lat. 

 43° N.; long. 140° 10' 30" E.), and station 4983 (lat. 43° 01' 35" N.; 

 long. 140° 10' 40" E.). 



Depth. — Three hundred and ninety to four hundred and twenty- 

 eight fathoms in green mud. 



Young specimens differ from the adults in having the tubercles on 

 the head replaced by spines, which are, however, not very long. 



This sj3ecies is very close to At'cturus haffini var. tuhej'osus Sars, but 

 differs in the much larger eyes, in having two large and well devel- 

 oped tubercles on the head, and in having two distinct, though small, 

 tubercles on each one of the segments of the thorax, and no tubercles 

 on the first two segments of the abdomen. This species is also dis- 

 tinct from Arctm'us ha-ffini var. intermedia Norman.'' 



Tyi)e-specimen.— Cat. No. 39510, U.S.N.M. 



ARCTURUS GLABER Benedict. 



ArcUiriis glahrus Benedict, Proc. Biol. Soc. Wash., vol. 12, 1898, p. 46. 



Arcturuft gUibcr Richardson, Proc. U. S. Nat. Mus., vol. 21, 1899, p. 855; 

 Ann. Mag. Nat. Hist. (7), vol. 14, 1899, p. 277; American Naturalist, vol. 34, 

 1900, p. 230 ; Bull. U. S. Nat. Mus., No. 54, 1905, pp. 330-331. 



Localities. — Station 4782 on the way from Agattu Island to Chi- 

 chagof Harbor, Attn Island, by the Semichi Islands, Aleutians, at 

 East Cape, Attn Island, S. 22° W., 4 miles (lat. 52° 55' N.; long. 

 173° 27' E.) ; station 3253, between Bristol Bay and Pribilof Islands, 

 Alaska. 



Depth. — Thirty-six to fifty-seven fathoms. 



ARCTURUS TRIT.ffiNIATUS, new species. 



Body narrow, elongate, a little more than four times as long as 

 wide (44 mm. : 19 mm, ) . Surface perfectly smooth. Color, in alcohol, 

 yellow, with numerous brown spots close together, covering the entire 

 surface of the body, with the exception of three longitudinal bands 

 of yellow, one median, and a lateral band on either side, which ex- 

 tend the entire length of the body to about the middle of the terminal 

 segment. The median longitudinal band stops at the base of the 

 terminal segment. 



"Ann. Mag. Nat. Hist. (7), vol. 14, 1904, p. 445. 



