60 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.21 



with E. lucasi and E. rubellula, one or both of which must be considered 

 endemic, is remarkable. None of the three seems overly abundant; in 

 fact, E. rubellula is exceedingly rare. 



The male first pleopod (Plate B, fig. 5) is distinctive, having a blunt 

 thumb process, liberally studded with short spines, opposed to the 

 finger-like terminal projection. 



The range of the species is extended as a result of Velero III explora- 

 tion from the Perlas Islands of Panama to Punta Santa Elena, Ecuador, 

 the village of La Libertad being situated on Santa Elena Bay. 



Genus EUPROGNATHA Stimpson 



Euprognatha Stimpson, 1871b, p. 122. A. Milne Edwards, 1878, p. 

 182. Miers, 1879c, p. 645. Rathbun, 1901, p. 57; 1925, p. 95. 



Type: The Atlantic Euprognatha rastellifera Stimpson, 1871, by 

 monotypy. 



Description: Carapace pyriform. Rostrum short, bifid, horns minute 

 and divergent. Interantennulary spine present, either salient and point- 

 ing forward and downward at a much lower level than rostrum, or 

 rudimentary. Basal antennal article narrowly triangular, with an outer 

 and an inner granulate or dentate crest; armed at anterior extremity 

 with a slender spine reaching forward as far or nearly as far as do the 

 rostral horns; movable part of antenna exposed from its insertion. A 

 spine or tubercle on orbital arch. Eye peduncle short, with a tubercle at 

 the emargination of cornea. Postocular spine reaching beyond extremity 

 of eye. Merus of external maxillipeds somewhat L-shaped, strongly pro- 

 duced beyond insertion of palpus in front and at posterointernal angle. 

 Abdomen of male with last two segments coalesced. 



Chelipeds with palms dilated ; fingers in the male slightly gaping. 

 Ambulatory legs of first pair much the longest, the others decreasing 

 regularly in length. Dactyli long and slender, more than half the length 

 of propodal [segments]. These crabs almost naked, the ambulatory legs 

 with a few curled setae above. (Rathbun, modified) 



In conformity with Balss (1929), the presence or absence of an 

 interantennular spine is here considered a generic character. Unquestion- 

 ably the spine is present in Euprognatha, of which E. rastellifera is the 

 type. Rathbun's subsequent modification (1901, 1925) of the original 

 description to admit a species described as without an interantennular 

 spine is therefore inadmissible, and E. bifida, if actually lacking this 

 character as Rathbun believed, could scarcely find lodgment in Stimp- 



