COMPLETE HAIG : EASTERN PACIFIC PORCELLANIDAE 143 



Bahia Pifias, Panama, 2-4 fathoms; January 29, 1935; Velero III 

 station 444-35 ; one male, one ovigerous female. 



Bahia Octavia, Colombia, shore; January 28, 1935; Velero III 

 station 435-35 ; one male, one ovigerous female. 



Measurernents: Males, 3,2 to 4.9 mm; ovigerous females, 3.3 to 5.7 

 mm. The following table, which is based on all known specimens, illus- 

 trates the marked difference in the length-width ratio in the two sexes. 



Color: Color of a dry specimen red washed with yellow; tips of the 

 fingers white. (A. Milne Edwards) 



Ecology: Two Velero III specimens were recovered from coral in 

 shallow water, and two others from coral taken in 2-4 fathoms. Speci- 

 mens taken by the Askoy Expedition were from coral at a depth of 2 

 to 3.5 fathoms. Habitat data are not available for the holotype or for 

 specimens taken on reefs at Balboa by Melbourne Ward. 



Ovigerous females were collected in January and in April. 



Relationships: Pachycheles crassus is closely related to P. acklei- 

 aniis A. Milne Edwards, 1880, a western Atlantic species. Both species 

 are transversely elongate, with coarsely granular chelipeds, and both 

 have a five-plated telson and lack male pleopods. In addition, both 

 have strong fixed spines on the posterior margin of the dactylus of 

 the walking legs, somewhat as in Polyonyx; as far as the writer is 

 aware, this character is found in no other members of the genus Pachy- 

 cheles. In P. ackleianiis the manus of the cheliped is less swollen than 

 in P. crassus, and there is a distinct tubercle near the base of the pollex, 

 on the distal side of which is a fine pubescence; the granules on the 

 chelipeds tend to form longitudinal rows, instead of being evenly dis- 

 tributed ; and there are scattered setae on the merus of the walking 

 legs. 



Remarks: A specimen was sent to Mr. Jacques Forest of the Paris 

 Museum, who kindly compared it with the holotype and confirmed its 

 identity with the present species. The type, a dry specimen in poor con- 

 dition, is labelled "Mr. de Follin — He aux Perles (Panama)." 



