PART 1 GARTH : PACIFIC OXYRHYNCHA 169 



Depth: To 45 fathoms. (Rathbun, 1892) Hancock specimens were 

 obtained from shore to 20 fathoms only. 



Size and sex: Males in the present series are from 5.5 to 22.1 mm, 

 females from 6.8 to 21.7 mm, ovigerous females from 9.4 to 19.3 mm. 

 A young specimen only 3.6 mm long was cracked from Pocillopora coral. 



Breeding: Ovigerous females were encountered by Hancock expedi- 

 tions in the Gulf of California in March, in Costa Rican waters in Feb- 

 ruary, and at Tres Marias Islands, Mexico, and Taboga Island, Panama, 

 in May. 



Remarks: Although primarily a Gulf of California species, as at- 

 tested by the overwhelming number of records from stations north of 

 Mazatlan, the type locality, Pitho picteti is appearing with increasing 

 frequency among collections from the Bay of Panama, as shown by 

 records of Boone, Finnegan, and of the Velero III. Worthy of note is 

 the extension of range from Magdalena Bay on the Lower California 

 west coast northward to San Ignacio and Scammon Lagoons, the speci- 

 mens having been obtained by Martin W. Johnson and M. Woodbridge 

 Williams, respectively. Significant also is the taking of P. picteti in the 

 same dredge haul with P. sexdentata at Tres Marias Islands and at Los 

 Frailes in the southern part of the Gulf of California. In Panamanian 

 waters inhabited by P. picteti and P. quinquedentata, the two species 

 appear to occur in segregated colonies, the former having been dredged 

 three times at Bahia Honda, the latter twice at Taboga Island. 



As compared with Pitho quinquedentata, P. picteti is generally larger, 

 but with a weakly developed male cheliped which is almost equaled in 

 length by the first walking leg. Its strong tuberculation and rough gran- 

 ulation serve at once to distinguish it from the much smoother P. quin- 

 quedentata and the finely granulate P. sexdentata. The extremely broad 

 first free antennal segment of P. picteti is not met with in either of the 

 other species. 



The key and diagnostic characters given above depart from the origi- 

 nal description with respect to the male cheliped. It is apparent that an 

 occasional male may have the elongated cheliped with the hand nearly as 

 long as the carapace, and that the specimen figured by Saussure and the 

 one described by Lockington as Micippa ovata var. laevis were of this 

 type. The presence of a transverse line of tubercles above the posterior 

 margin of the carapace serves to distinguish Saussure's specimen from 

 Bell's Pitho quinquedentata, with which species the elongated cheliped is 

 here associated. All Hancock expeditions males of P. picteti, however, are 

 of the short-handed type figured by Rathbun (1925, pi. 130, figs. 2 and 

 3 ) , who apparently also was willing to overlook this discrepancy. 



