PART 1 GARTH : PACIFIC OXYRHYNCHA 233 



Remarks: The specimen from Cabeza Ballena comes from within 

 sight of Stimpson's type locality, Cape San Lucas. The specimen from 

 San Marcos Island is believed to be the one figured by Rathbun (1925, 

 pi. 46, fig. 3; pi. 47, fig. 2). Although measuring only 11.0 mm, instead 

 of 11.2 mm, it conforms in all particulars, including the loss of the 

 right second ambulatory leg, which is detached in the bottle. Un- 

 fortunately, additional damage to the specimen has occurred since the 

 photograph was taken. 



Genus EPIALTOIDES, new genus 



Epialtus Rathbun, 1923a, p. 71 (part) ; 1925, p. 144 (part) ; not 

 Epialtus Milne Edwards. 



Type: Epialtus hiltoni Rathbun, 1923. 



Description: Similar to Epialtus, but with an entirely smooth or 

 posteriorly sculptured carapace; anterior margins of hepatic lobes 

 transverse or curving strongly forward. Preorbital tooth, when present, 

 prominent; postorbital tooth inconspicuous. Chelipeds of male robust, 

 often of a size grossly disproportionate to carapace and walking legs. 

 Ambulatory legs non-prehensile, propodus lacking either an inferior 

 tooth or cluster of setae. 



Abdomen with five free segments in both sexes. 



With the restriction of the genus Epialtus to those species possessing 

 six free abdominal somites in the male sex, it becomes necessary to erect 

 a new genus to accommodate three and possibly four American species, 

 the males of which have but five. Two of these, Epialtoides hiltoni and 

 E. kingsleyi, were described by Rathbun (1923a) as among "the group 

 of small species of Epialtus sometimes combined under the name E. 

 bituberculatus," irrespective of the fact that they (along with E. 

 peruvianus, here transferred to Eupleurodon) possessed one male ab- 

 dominal somite less. A third, Epialtus murphyi Garth (1948, p. 24), is 

 known only from the female sex and is included in Epialtoides tentatively 

 until the number of abdominal segments in the male can be ascertained. 

 A fourth species, Epialtoides paradigmus, is here described for the first 

 time. 



The three Pacific species share the common characters of the oblong, 

 bilobed rostrum and the strong preorbital tooth. The single Atlantic 

 species, Epialtoides kingsleyi, has a triangular rostrum and no preorbital 

 tooth ; however, it departs no more radically from its congeners than does 

 Epialtus sulcirostris from members of the six-segmented group. 



