340 BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



tudinal line. The first segment also has the sides produced in acute 

 processes, one on either side, not separated from the segment and 

 simulating the epimera of the last three thoracic seg- 

 ments. The last or terminal segment is very long, 

 11 mm., about one-fourth the entire length of the 

 body. At the base on either side, the lateral margin 

 is produced in a long, acute process. Halfway be- 

 tween the base and the apex of the segment, on the 

 dorsal surface, are two tubercles, one on either side 

 of the median longitudinal line. The apex of the seg- 

 ment is acutely pointed. 



The first four pairs of legs are slender, directed 

 forward, and thickly furnished with long slender hairs 

 FIG. 368. ARCTUEUS on the inferior margins of all the articles. The ter- 

 LIPED^'X isf XI minal article is minute; the three preceding articles 

 are long and slender. The first pair of legs are much 

 shorter than the three following pairs. The last three pairs of legs 

 are stout and ambulatory in character. The entire surface of the 

 body, the antennae, legs, etc., is densely granular. 



ARCTURUS BAFFINI var. TUBEROSUS Sars. 



Arcturus tuberosus SABS, Archiv Math, og Naturvid., 1877, p. 350. 



Arcturus baffini var. fdldeni MIERS, Ann. Mag. Nat. Hist. (4) , XIX, 1877, p. 64, 



pi. in, fig. 1. 

 Arcturus tuberosus SARS, Norwegian North Atlantic Expedition, Crustacea, 1885, 



p. 102, pi. ix, fig. 22. 

 Arcturus feildeni BENEDICT, Proc. Biol. Soc. Washington, XII, 1898, p. 44. 



RICHARDSON, American Naturalist, XXXIV, 1900, p. 230; Proc. U. S. Nat. 



Mus., XXIII, 1901, p. 549. 



Arcturus baffini ORTMANN, Proc. Acad. Nat. Sci. Phila., 1901, pp. 156-157. 

 Arcturus baffini var. tuberosus NORMAN, Ann. Mag. Nat. Hist. (7), XIV, 1904, 



p. 445. 



Localities. Camp Clay, Cape Sabine; Davis Straits; off Churchill, 

 Hudson Bay; Granville Bay; Elsmere Land or Greenland. 



Depth. 20-30 fathoms clay bottom ; small stones and gravel. 



Body narrow, elongate, a little over eight times longer than wide, 

 4 mm.: 35 mm., not including the antennae. 



The head is as wide as long, 4 mm. : 4 mm., with the anterior mar- 

 gin deeply excavate. The eyes are small, wider than long, composite, 

 and situated at the sides of the head about halfway between the ante- 

 rior and the posterior margins. The first pair of antennas have the 

 basal article long and somewhat dilated; the second and third articles 

 are subequal, and the two together are equal in length to the basal 



Norman proposes a third variety, A. baffini var. intermedia, in \yhich the tubercles 

 on the first four segments of the thorax and the elevation on the head are greatly 

 reduced in size, but on the fifth and succeeding segments they are as well repre- 

 sented as in the typical form. 



