444 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 21 



Subgenus Pseudolambrus Paulson 



Pseudolambrus Paulson, 1875, p. 9. Rathbun, 1925, p. 528. 



Parthenolambrus A. Milne Edwards, 1878, p. 148; type: Parthenope 

 tarpeius Adams and White, 1849, by subsequent designation of 

 Rathbun (1925). Alcock, 1895, p. 275. 



Parthenopoides Miers, 1879c, p. 672 (part) ; type: Lambrus massena 

 Roux, 1830, by original designation. 



Type: The Indo-Pacific Parthenope calappoides Adams and White, 

 1849, type of Pseudolambrus Paulson by monotypy. 



Description: Carapace semielliptical or semicircular, with a nearly 

 straight posterior margin, the posterolateral angles being strongly pro- 

 duced. Chelipeds of no great length, never sharply serrate, and with the 

 hands and arms indefinitely contorted. Rostrum more or less deflexed. 

 (Alcock) 



Parthenope (Pseudolambrus) triangula (Stimpson) 

 Plate Z,, Figs. 2, 2a ; Plate 49, Fig. 2 



Lambrus triangulus Stimpson, 1860b, p. 201. A. Milne Edwards, 1878, 



p. 152, pi. 31, figs. 1-lc. 

 Parthenope (Pseudolambrus) triangula, Rathbun, 1925, p. 528, pi. 278, 

 figs. 1-3. Crane, 1937, p. 65, pi. 5, fig. 18. Garth, 1946, p. 410, 

 pi. 69, fig. 1. 



Type: Female holotype, length 14.0 mm, width 17.5 mm; not extant. 



Type locality: Cape San Lucas, Lower California, Mexico; John 

 Xantus, collector. 



Localities subsequently reported, with collectors: Lower California, 

 Mexico: San Lucas Bay, 3 fathoms, Zaca (Crane). Ecuador: Galapagos 

 Islands, 2-70 fathoms, Velero III (Garth). 



Atlantic analogue: None. The subgenus is excluded from the western 

 Atlantic. 



Diagnosis: Carapace an equilateral triangle; branchial regions pro- 

 duced to cover meri of ambulatory legs. Rostrum obtuse, deflexed. Base 

 of movable part of antenna protected on each side by an over-arching 

 tooth. Relatively few (8 or 9) teeth on upper margin of manus. Male 

 first pleopod stout, cylindrical, basally angled, terminally capitate, groove 

 open throughout length, a row of short marginal setae, a few longer 

 setae on marginal lip, and many longer setae on rounded terminal por- 

 tion. Male second pleopod about three-fifths length of first, sinuous, tip 

 corneous, denticulate, a subterminal denticulate tooth. 



