364 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 5 



807-38. Academy Bay, Indefatigable Island, 10-25 fms, Jan. 24, 1938, 

 1 male, 10 young (AHF no. 38031). 



Measurements. — Male : length 20.4 mm, width 20.9 mm. 



Color in life. — Ground color of carapace light olive gray with numer- 

 ous deep purplish vinaceous spots. Ambulatory legs French gray with 

 stripes of purplish lilac, salmon color at distal end of merus. Dactyls light 

 amber yellow. Eyestalks French gray; eyes light green. (Petersen) 



Habitat. — Sand, sand and coral, sand and rock. 



Depth. — 2-70 fms; 1 shore record, presumably extreme low tide. 



Remarks. — C. bairdii is the only Galapagos oxystome to be found also 

 in the Atlantic. It is even commoner in dredge hauls than the foregoing 

 species, Mursia gaudichaudii (Milne Edwards), but has a much more 

 normal range, both geographic and bathymetric. Its Pacific distribution 

 coincides nicely with the belt of warm water extending from Lower Cali- 

 fornia to Cape Santa Elena, Ecuador, its bathymetric range to the surface 

 layers of wanner water also. 



Subfamily MaTUTINAE 



Genus OSACHILA Stimpson, 1871 



Osachila galapagensis Rathbun 



Plate 52, Figs. 1-7 



Osachila galapagensis Rathbun, Proc. Biol. Soc. Washington, vol. 48, 

 p. 3, 1935; Bull. 166, U.S. Nat. Mus., p. 254, pi. 82, fig. 5; pi. 83, 

 fig. 3, 1937. 



Type locality. — Wenman Island, Galapagos Islands, 100-150 fms. 

 Type.—\]?>NM No. 69215. 



Range. — Known only from the Galapagos Islands. 

 Atlantic analogue. — Not O. antillensis Rathbun (see Remarks 

 below) . 



Diagnosis. — Carapace granulate, length little more than three fourths 

 width. Rostrum thick, bilobed. Anterolateral margin completely denticu- 

 late, teeth in clusters of 3. Postbranchial prominence high ; outer branchial 

 elevation extending both forward and backward of lateral angle. Leg 

 surfaces nearly smooth, edges dentate. 



Material examined (14 specimens from 6 stations). — 

 143-34. Wenman Island, 100-150 fms, Jan. 11, 1934, 1 male, 4 fe- 

 males (USNM No. 69215), the type series; 2 females (1 ovig., 1 

 illustrated) (AHF no. 34045). 

 147-34. Tagus Cove, Albemarle Island, 30 fms, Jan. 13, 1934, 1 male 

 (USNM No. 69212). 



