228 BULLETIN 152, UNITED STATES NATIONAL MUSEUM 



Trichocarcinus recurvidens Walker, Trans. Liverpool Biol. Soc, vol. 12, 189S, 



p. 271, pi. 15, figs. 1-16.29 

 Trichocarcinus ivalkeri Holmes, Occas. Papers Calif. Acad. Sci., vol. 7, 1900, 



p. 53 (new name for recurvidens Walker). 

 Cancer oregonensis Rathbun, Proc. U. S. Nat. Mas., vol. 21, 1898, p. 581; Harri- 

 man Alaska Exped., vol. 10, 1904, p. 178, pi. 7, fig. 1. — Schmitt, Univ. Calif. 

 Publ. Zool., vol. 23, 1921, p. 234, pi. 36, figs. 3 and 4. 



Diagnosis. — Antero-lateral and postero-lateral margins not meeting 

 at a distinct angle. Carapace widest at seventh or eighth tooth. 

 Merus of outer maxillipeds with antero-external angle produced. 



Description. — Carapace elliptical, more or less evenly rounded at 

 sides, antero-lateral and postero-lateral margins not meeting at a 

 distinct angle, carapace widest at seventh or eighth tooth; 12 or 13 

 teeth; fronto-orbital width nearly one-half width of carapace. All 

 teeth with granulated edges. Front between antennae truncate, 

 advanced slightly beyond line of outer orbital angles and separated 

 by a rounded sinus from inner orbital angles; median tooth very small. 

 Middle tooth of orbit lobiform, reflexed. The first 10 lateral teeth of 

 carapace similar, curved forward, spine-tipped except for the first 2; 

 last 2 or 3 teeth small and blunt. Surface coarsely and densely 

 granulate, and lumpy, the granulation coarser on the elevations. 

 Carpus of chelipeds tuberculate above and with a short spine at 

 inner angle and a tooth below it; hand thick and high, the short upper 

 edge of palm with 2 rows of tubercles, outer surface with 5 finely 

 granulate fines; dark color of fingers reaching nearly to their bases. 

 Legs hairy. 



Variations. — In the female the carapace is more uneven than in the 

 male, the elevations higher and more pronounced. In many cases 

 (form a, pi. 96, fig. 3) this is carried to an extreme and the sexes are 

 very unlike; in the female the elevations are isolated, baccate and 

 flattened, the intervening furrows quite smooth; the protogastric 

 lobes are largest and highest, the narrow part of the mesogastric 

 region is a short linear row of single berries, the hepatic region has 

 a Y-shaped lobe, the arms of the Y extending to the lateral teeth; 

 a fan-shaped pattern of 6 segments diverges from the posterior margin. 

 In some individuals of this type the lateral teeth are shortened and 

 their ends bluntly rounded (3076). The chelipeds are rougher in the 

 female than in the male. 



Form h (pi. 136, fig. 1) is represented by a male (17424) which is 

 even further removed from typical oregonensis. The elevations of 

 the carapace are small, hemispherical, the largest and most sharply 

 defined on the summit of each protogastric region; the mesogastric 

 boss is small. On the branchial region are three bosses, of which the 2 

 largest are placed longitudinally at the middle of the region and are 



» Walker, p. 272, calls his specimen a male; I have found the same ornamentation only in the female, or 

 form a. 



