PART 1 GARTH : PACIFIC OXYRHYNCHA 439 



Parthenope (Platylambrus) exilipes (Rathbun) 

 Plate Zi, Figs. 3, 3a ; Plate 48, Fig. 2 



Lambrus (Parthenolambrus) exilipes Rathbun, 1893b, p. 234. 

 Lambrus hassleri Faxon, 1893, p. 152; type localities, Albatross stations 

 3368 and 3427 ; cotypes, U.S.N.M. No. 20599, M.C.Z. No. 4481 ; 

 1895, p. 14, pi. 3, figs. 1, la. 

 Lambrus exilipes, Rathbun, 1898, p. 581. 



Parthenope (Platylambrus) exilipes, Rathbun, 1925, p. 523, pis. 184, 

 185; pi. 277, figs. 1, 2. Boone, 1927, p. 172, fig. 57. Crane, 1937, 

 p. 64. Garth, 1946, p. 409, pi. 69, fig. 2. 



Type: Male holotype, U.S.N.M. No. 17365, length 10 mm, width 

 13 mm, cheliped 25 mm. 



Type locality: Off San Domingo Point, Lower California, Mexico. 

 74 fathoms, Albatross station 3043. 



Localities subsequently reported, with collectors: Lower California, 

 Mexico: off Cape San Lucas, 31 fathoms, Albatross (Rathbun, 1898) , 

 Gulf of California, Mexico: Arena Bank, 20-50 fathoms, and Gorda 

 Banks, 40-75 fathoms, Zaca (Crane) ; off Tres Marias Islands, 80 

 fathoms, Albatross station 3427 (Faxon, 1893, as Lambrus hassleri). 

 Costa Rica: Cocos Island, 66 fathoms, Albatross station 3368 (Faxon, 

 1893, as Lambrus hassleri). Panama: Bay of Panama, 51.5 fathoms, 

 Albatross (Rathbun, 1898). Ecuador: off Charles Island, Galapagos 

 Islands, 78.5 fathoms, Albatross (Rathbun, 1898). For an additional 

 12 Galapagos stations see Garth (1946, p. 409). 



Atlantic analogue: Parthenope (Platylambrus) pourtalesi (Stimp- 

 son ) . 



Diagnosis: Carapace high, tuberculate ; interregional depressions 

 shallow; hepatic and interbranchial pits deep. Tooth at lateral angle 

 largest of marginal teeth. Four prominent median and one large bran- 

 chial tubercle. Rostrum channeled, trilobate. Propodi and dactyli furred. 

 Male first pleopod stout, tapering to tip ; tip truncate and twisted ; a 

 cluster of setae on lip of groove; other short setae lateral and terminal. 

 Male second pleopod nearly as long as first, sinuous, tip elongate, slen- 

 der, a subterminal denticulate tooth. 



Description: Carapace about one-third broader than long; narrow at 

 the hepatic regions, spreading at the branchial regions; a cavity near the 

 margin between the branchial and the small hepatic region; a large 

 cavity between the branchial and the cardiac and gastric regions. Median 

 tubercles four, one large on the posterior portion of the gastric region, 

 one small on the genital, one large on the cardiac, and one small on the 



