406 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 5 



Genus TYGHE Bell, 1835 

 Tyche lamellifrons Bell 

 Plate 54, Figs. 1-6 



Tyche lamellifrons Bell, Proc. Zool. Soc. London, vol. 3, p. 173, 1835 

 (1836) ; Trans. Zool. Soc. London, vol. 2, p. 58, pi. 12, figs. 3, 3f-j, 

 1836. Rathbun, Bull. 129, U.S. Nat. Mus., p. 508, pi. 273, figs. 1-6, 

 and synonymy, 1925. Crane, Zoologica, vol. 22, no. 3, p. 64, 1937. 

 Type locality. — Panama. 

 Type. — In Brit. Mus. 



Range. — Gulf of California (Albatross) to Panama (Bell) ; to a 

 depth of 29 fms (Crane). 



Atlantic analogue. — T. emarginata White. 



Diagnosis. — Preorbital horns divergent, exceeding rostral horns. 

 Posterior margin of carapace faintly trilobate. Orbits concealing eyestalks 

 to extremities. 



Material examined (6 specimens from 6 stations). — 

 69-33. Albemarle Point, Albemarle Island, shore, Feb. 11, 1933, 1 



female (illustrated). 

 167-34. Post Office Bay, Charles Island, 15 fms, Jan. 19, 1934, 1 male 



(illustrated in part). 

 311-35. Marchena Island, 20 fms, Dec. 3, 1934, 1 young. 

 343-35. Sulivan Bay, James Island, shore, Dec. 12, 1934, 1 male. 

 355-35. West of Gardner Island, Hood Island, 12 fms, Dec. 17, 1934, 



1 male. 

 784-35. Darwin Bay, Tower Island, shore, Jan. 17, 1938, 1 young. 

 Measure/nents. — Largest specimen, female: length 29.0 mm, width 

 18.0 mm; male: length 24.2 mm, width 15.0 mm, cheliped 19.0 mm, 

 chela 9.1 mm. 



Color in life. — ^A young specimen: carapace uniform Sudan brown. 

 Eyestalk amber, eye buff yellow. Cheliped same as carapace but hand a 

 tone lighter, color fading gradually to very pale tips. Ambulatory legs 

 lighter than carapace; nail of dactyl clear pale amber. (Petersen) 



Habitat. — Sandy bottom (Bell) with weed (Crane). Velero III 

 specimens were all taken either on rocky shore, or with tangles, indicating 

 rocky bottom. 



Depth. — Shore to 29 fms. 



Remarks. — An adult female, measuring 29 mm in length by 18 mm 

 in width, appears to be the largest specimen on record. The preorbital 

 horns exceed the rostral and are strongly divergent, as in the Atlantic 

 species, T. emarginata White, thus differing from the diagnostic char- 



