366 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.21 



Remarks: A great deal more is known about this species than in 

 1925, when Rathbun was able to list, in addition to the non-extant type 

 from Panama, only 2 males and 2 females collected in the Perlas Islands 

 by Garman in 1875. The range of the species has been extended suc- 

 cessively to Gorgona and the Galapagos Islands by the St. George, to 

 Ecuador by the Askoy, and north to Port Parker, Costa Rica, by the 

 Zaca. For all this, it remains restricted to the Bay of Panama, broadly 

 defined to include Pacific Colombia and Ecuador to Punta Santa Elena, 

 which, together with the Galapagos Islands, forms the southern half of 

 the Panamic faunal province. 



The elongated chelipeds of the adult male and the truncate front 

 make it impossible to confuse this small species with any other Mithrax. 

 However, the large eyes, long antennae, and reduced orbital teeth make 

 it easy to confuse it with Teleophrys cristulipes, which occupies the same 

 range and ecological niche, the Pocillopora colony. The cristate legs of 

 the latter and the almost smooth legs of Mithrax (Mithrax) pygmaeus 

 will serve to differentiate these two when a glance at the carapace alone 

 might not suffice. 



Mithrax (Mithrax) spinipes (Bell) 

 Plate V, Fig. 8 ; Plate 42, Fig. 1 



Pisa spinipes Bell, 1835b, p. 171 ; 1836, p. 50, pi. 9, figs. 6, 6s-u. 



Nemausa spinipes, A. Milne Edwards, 1875, p. 82. 



Mithrax (Nemausa) spinipes, Miers, 1886, p. 85. Rathbun, 1892, p. 259. 



Mithrax spinipes, Rathbun, 1910, p. 575. 



Mithrax (Mithrax) spinipes, Rathbun, 1925, p. 391, pi. 136, figs. 3, 4; 



pi. 262, fig. 5. Boone, 1927, p. 154, fig. 48. Sivertsen, 1933, p. 12. 



Crane, 1937, p. 60. Garth, 1946, p. 388, pi. 65, figs. 5, 6. 

 Mithrax (Mithrax) mexicanus Glassell, 1936, p. 213; type locality, 



3 mi. NE of Cape Pulmo, Gulf of California; male holotype, 



N.Y.Z.S. No. 36,712. Crane, 1937, p. 60, pi. 3, figs. 10, 11. 

 ..-..Types: Male, length 16.9 mm, width 8.5 mm, and female, cotypes, 

 originally in the Museum of the Zoological Society [London] and the 

 Bell Museum, respectively, no longer extant. 



Type localities: Galapagos Islands, 16 fathoms; Santa Elena, Ecua- 

 dor, 6 fathoms; Hugh Cuming, collector. 



Localities subsequently reported, with collectors: Gulf of California, 

 Mexico: Off San Jose Island, 33 fathoms, Albatross (Rathbun, 1892) ; 

 Arena Bank, 2.5-45 fathoms, Zaca (Crane) ; 3 miles northeast of Cape 

 P.ulmo, 50 "fathoms,. Zaca (Glassell, Crane, as Mithrax (Mithrax) 



