156 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 24 



two Strong, granulate-edged teeth, a third occasionally present; surface 

 covered with short rugae or much-flattened granules, more project- 

 ing toward posterior margin, and with short, non-plumose setae. Manus 

 and fingers granulate and covered with long, non-plumose setae ; fingers 

 long and slender, gaping in major cheliped, meeting for entire length in 

 minor cheliped, gape with long setae extending onto ventral surface of 

 manus near articulation with dactylus. 



All segments of walking legs with long setae. 



Telson of abdomen with seven plates. A pair of pleopods in male. 



Variations : Occasional female specimens have the telson of the abdo- 

 men incompletely seven-plated ; however, this condition was observed 

 only three or four times among the 50 females examined and cannot be 

 considered characteristic. 



Material examined: See Table 49. 



Measurements: Males, 3.0 to 8.2 mm; non-ovigerous females, 2.1 to 

 6.5 mm; ovigerous females, 2.3 to 8.5 mm. The ovigerous female holo- 

 type of Pachycheles panamensis measures 6.5 mm in length by 7.0 mm 

 in breadth ; the male holotype of P. sonorensis, 7.0 by 7.5 mm. 



Color: Ground color in alcohol a pink-tinted cream overlaid with 

 numerous small, red, irregular spots; lighter on the ventral side, but 

 still spotted. (Glassell, 1937, of Pachycheles sonorensis) 



Ecology: Occurs most commonly in the intertidal zone, under stones 

 and in interstices of coral. The Velero III dredged it from a sand bot- 

 tom at 4 fathoms off La Libertad, Ecuador, and Velero IV collectors re- 

 covered it from masses of sponge dredged in 1-4 fathoms off Acapulco, 

 Mexico. 



Ovigerous females have been encountered in every month from De- 

 cember through April. 



Remarks: Steinbeck and Ricketts (1941, p. 456) noted that, ac- 

 cording to a personal communication from S. A. Glassell, the latter 

 writer's Pachycheles sonorensis is a synonym of P. panamensis. The 

 types of both nominal species were examined in connection with this 

 report. 



Specimens from the Bahamas identified by Ortmann (1897, p. 293) 

 as Pachycheles panamensis are almost certainly not this species, which 

 has not otherwise been reported from the Atlantic coast. Ortmann's 

 specimens may have been P. pilosus (H. Milne Edwards), the only west- 

 ern Atlantic porcellanid with which P. panamensis might be confused. 



