No. 10 garth: BRACHYURAN fauna of the GALAPAGOS 379 



Genus SPHENOGARGINUS A. Milne Edwards, 1875 



Sphenocarcinus agassizi Rathbun 



Plate 63, Fig. 2 



Sphenocarcinus agassizi Rathbun, Proc. U.S. Nat. Mus., vol. 16, p. 231, 

 1893 ; Bull. 129, U.S. Nat. Mus., p. 188, pi. 63 ; pi. 223, figs. 1 and 

 2, 1925. Faxon, Mem. Mus. Comp. Zool., vol. 18, p. 7, pi. 1, figs. 

 3 and 3a, 1895. Crane, Zoologica, vol. 22, no. 3, p. 58, 1937. 



Type locality. — Gulf of California, 14 fms. 



Type.—\]?>NM No. 17343. 



Range. — From Cape Tepoca, Gulf of California (Albatross), to 

 Panama (Albatross); 14 to 71 fms. 



Atlantic analogue. — S. corrosus A. Milne Edwards. 



Diagnosis. — Rostrum formed of 2 blunt spines contiguous to tips. 

 Lateral margins of carapace coarsely dentate. 



Material examined (5 specimens from 2 stations). — 

 792-38. Off Daphne Minor Island, 70-80 fms, Jan. 20, 1938, 1 male, 



3 young. 

 810-38. Barrington Island, 48-73 fms, Jan. 26, 1938, 1 female (photo- 

 graphed). 



Measurements. — Largest specimen, female: length 24.6 mm, width 

 18.8 mm, rostrum 10.0 mm, cheliped 19.2 mm, chela 8.5 mm, first ambu- 

 latory leg 26.8 mm. 



Color in life. — Ground color of carapace pink with grayish hue. A 

 pair of broad bands of vinaceous rufous extending from behind front to 

 intestinal region, one on either side of median line. Median frontal por- 

 tion light cerulean blue. Anterolateral teeth yellow orange. Cheliped 

 orange buff at base to yellow cinamon buff on hand and fingers. First three 

 ambulatory legs pale orange cinnamon, last leg yellow cinnamon buff 

 banded with vinaceous rufous. (Petersen) 



Habitat. — Sand, mud and sand. 



Depth.— \4-80 fms. 



Remarks. — The finding of this species in 1938 and not in previous 

 years is attributable to the deeper dredging attempted. S. agassizi is com- 

 mon enough in the Gulf of California but has not before been taken in 

 the Galapagos Islands. 



No particular significance is attached to the circumstance of taking 

 the Daphne Minor specimens in association with a holothurian, as none 

 of the subfamily Acanthonychinae, to which Sphenocarcinus belongs, are 

 known to the writer to be commensal in habitat. 



