362 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.21 



of palm 2.5 mm, ambulatory legs 21.3, 18.4, 17.0, and 14.0 mm, respec- 

 tively. Ovigerous female: length 13.2 mm, width including spines 12.0 

 mm, without spines 11.1 mm. 



Color in life: Carapace and eyes dull Eugenia red. Merus and carpus 

 of cheliped orange red, hand and fingers bright chrome orange, fading 

 on finger tips. Ambulatory legs pale orange with tiny blotches of red. 

 Ventral side brilliant Eugenia red on frontal portion fading to olive buff 

 on superior areas. (Petersen, of a specimen from Puerto Refugio, Angel 

 de la Guarda Island. Gulf of California) Uniformly bright carmine. 

 Chelipeds and ambulatory legs a little lighter than carapace. Fingers 

 white tipped. Eyes garnet brown. Abdomen and sternum cream buff; 

 pterygostomian region and maxillipeds light carmine. (Petersen, of a 

 specimen from San Gabriel Bay, Espiritu Santo Island, Gulf of Cali- 

 fornia) 



Habitat: Sand and shell, shell, broken coral. (Rathbun) Sandy bot- 

 tom. (Crane) A primary breakdown of the 34 Hancock expeditions 

 stations shows 10 rock, 10 sand, 6 mud, and 8 organic (coral, nullipore, 

 and coralline) bottom. Shell was present with sand on 4 occasions and 

 nullipore with rock on 3 occasions. 



Depth: Low tide level to 40 fathoms; exceptionally (off Panama) 

 to 50 fathoms. 



Size and sex: The extensive series contains young from 2.5 mm, males 

 from 5.4 to 16.6 mm, females from 5.8 to 14.3 mm, ovigerous females 

 from 8.4 to 13.2 mm. In this species the largest specimens are not from 

 the Gulf of California, the male and female measured above coming 

 from Colombia and Panama, respectively. 



Breeding: Egg-bearing females were encountered in the Gulf of 

 California in February, off Panama in February and March, off Colom- 

 bia in January, and off Ecuador in February. 



Remarks: It will be noted that the single specimen from Socorro 

 Island has been placed with typical Mithrax (Mithrax) sinensis rather 

 than with p specimens from Clarion Island, here considered a subspecies 

 of M. (M.) sinensis. Specimens from Pinas Bay, Panama, and Port 

 Utria and Gorgona Island, Colombia, might also be segregated from 

 those occurring from northern Panama northward on the basis of their 

 greater spinulosity, specimens from the Gulf of California, in particular 

 those from stations 513-36 and 515-36, being quite smooth. Records for 

 the species along the mainland from Lower California to northern 

 Panama are lacking. 



