100 ALLAX HANCOCK PACIFIC EXPEDITIONS VOL.21 



As noted by Rathbun (1925, p. 63) with respect to a specimen 

 from Magdalena Bay, Lower California (U.S.N.M. No. 50641), a 

 sharp supraorbital tubercle is present in Hancock expeditions specimens 

 from Rocky Point to Puerto Refugio, Angel de la Guarda Island, Gulf 

 of California, and in Kenyon-Williams expedition specimens from Cedros 

 Island and Scammon Lagoon, west coast of Lower California. This 

 condition is associated with a longer rostrum, a sharp hepatic spine, which 

 exhibit accessor}' spinules, and a sharp- granulate sternum, the 

 granules extending onto the bases of the cheliped and walking legs. A 

 subspecir.: designation might well be applied to this form, which appears 

 to predominate among specimens from northern localities. 



Material examined: A total of 122 specimens from 49 stations. (See 

 Table 14) From Cedros Island and Scammon Lagoon to Magdalena 

 Bay. west coast of Lower California, and from Rocky* Point, Gulf of 

 California, Mexico, to La Libertad, Ecuador. 



Measurements: Largest specimen, male: length 8.8 mm, width 6.1 

 mm, cheliped 16 mm, chela 7.4 mm, dactyl 3.5 mm, second walking leg 

 10.6 mm (others missing). Female: length 7.7 mm, width 5.7 mm. 



Color in life: Light Sudan brown with a strong yellow-green hue. 

 Propodi and dactyli of ambulatory legs cream color. Ventral side pale 

 greenish-yellow. (Petersen, of a male from Taboga Island, Panama) 



Habitat: Crushed shell mud with a little weed. (Crane, 1937, p. 53) 

 Black mud and gray sand. (Garth, 1948) Sand bottom in nearly 60 

 per cent of the cases, with shell also present in about one-third of these. 

 Mud, with sand also present more often than not, accounts for the bulk 

 of the remainder. 



Depth: \ l / 2 to 25 fathoms, exceptionally to 56 fathoms. One shore 

 station in the upper reaches of the Gulf of California, where tidal ranges 

 are extreme. 



Size and sex: The smallest specimens in the Hancock series are 

 approximately 2.5 mm in length and are by no means post-larval. Sex 

 can be determined readily in all of them. The small size of egg-bearing 

 females is remarkable, one 3.5 mm specimen earlier labeled "young" 

 proving to be ovigerous. 4.0 mm is average size for gravid females, 5.5 

 mm maximum. Large males reach 8.5 and 8.8 mm, not as large, however, 

 as the 9.6 mm male reported by Crane (1937), nor as the male cotype, 

 a 10.7 mm specimen. 



Breeding: All females of a small series taken at La Libertad, 

 Ecuador, in February were ovigerous, as were nearly all females from 

 numerous lots from Costa Rica in the same month. Pre-zoeae ready for 



