32 CALIFORNIA ACADEMY OP SCIENCES. 



Hyas lyratus Dana. 



Hyas lyratus Dana, Am. Journ. Sci. (2), Vol. XI, 1851, p. 268; Crust. U.S. 

 Expl. Expd., Part I, 1852, p. 86, Pi. I, fig. 1. Stimpson, Journ. Bost. 

 See. Nat. Hist., Vol. VI, 1857, p. 450. Lockingtojst, Proc. Cal. Acad. 

 Sci., Vol. VII, 1877, p. 64. Miers, Challenger Keports, Vol. XVII, 

 1886, p. 47. Rathbun M., Proc. U. S. Nat. Mus., Vol. XVI, 1893, p. 

 72, PI. III. Newcombe, Bull. Nat. Hist. Soc. Brit. Col., 1893, p. 20. 



Carapace lyrate and furnished with blunt tubercles. Median region 

 tumid, and generally furnished with two elevations, one near the middle 

 and one behind; post-median region prominent, pustulate or roughened; 

 cardiac region furnished with a subcorneal elevation; branchial regions 

 elevated at the niiiddle and crossed by a more or less evident line of rounded 

 tubercles. Rostrum shorter than the width of the interorbital space, the 

 cleft between the horns narrow. A tooth on the anterior margin of the 

 optic peduncle. Basal antennal joint with a few small teeth on each mar- 

 gin and a prominent, smooth tubercle at the autero-external angle; second 

 joint dilated and almost entirely visible from above. A small tooth on 

 the first joint below the articulation of the second. Maxillipeds granu- 

 lated. Behind the eyes is an alate expansion, the anterior and posterior 

 margins of which are generally nearly parallel, outer margin long and a 

 little concave; anterior angle acute; a small tooth near the base of the 

 convex posterior margin of this expansion, behind which the side of the 

 carapace is quite deeply indented. Behind the alate expansion the margin 

 of the carapace is furnished with a row of small tubercles. Merus of the 

 chelipeds with a few small tubercles, which are more prominent at the 

 angles; hands narrow, compressed, smooth or granulated, the upper mar- 

 gin compressed and roughened by small tubercles; fingers nearly smooth. 

 The abdomen of the male is widest at the second and third segmenis, 

 behind which the sides run nearly parallel to the last joint, which is dis- 

 tally truncated and over twice as broad as long. Abdomen of the female 

 broadly elliptical, the joints increasing in length from the second to the 

 last. 



Locality of specimens described: — 



56° 40' N. 169° 20' W. 43 fms. 2 spms. 

 56° 58' N. 170° 09' W. 25 " 1 " 

 56° 34' N. 170° 17' W. 62 " 2 " 



This species ranges from the extreme end of the 

 Aleutian Islands to Paget Sound, whence it was first 

 reported by Dana. 



V^ik 



