86 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 5 



with two broad bands of orange. Carpus and propodus orange red, dac- 

 tylus white, touched with red at base. (Petersen, taken from a male 

 specimen secured in the Gulf of California at Velero Station 1059-40.) 



Remarks: The proposed species gives the North Pacific Ocean its 

 first representative of a genus found in the North and South Atlantic 

 and in the South Pacific. As might be expected, it is a more nearly perfect 

 analogue of the species from the North Atlantic, Pilumnoides nudifrons 

 (Stimpson) (1871), than of the Peruvian and Chilean P. perlatus 

 (Poeppig) (1836), type of the genus. With P. hassleri A. Milne Ed- 

 wards (1880) from Uruguay and the Straits of Magellan it has little 

 in common. 



Compared to P. nudifrons, the new species agrees remarkably on 

 structural points, such as orbital configuration, size and relationship of 

 the antennular and antennal areas, endostomial emargination, and shape 

 of the external maxilliped. The most remarkable conformity is in the 

 height and length of the fingers and the type and location of the pu- 

 bescence of the hand. (See pi. 23, fig. 2.) Dissimilarity is encountered in 

 the naked front of nudifrons, almost continuous instead of bilobate, its 

 four anterolateral teeth without denticles between, its almost smooth, 

 though hairy, carapace (except for hepatic tubercles), and its more hex- 

 agonal, less rotund appearance. 



Compared to P. perlatus, the new species lacks the two supraorbital 

 fissures, the compressed anterolateral margins, the transverse striae, in- 

 cluding the line inward from the lateral angle, and the smooth posterior 

 half of the carapace and ambulatory legs. The hands of perlatus are de- 

 void of hairs, and the merus of the third maxilliped is rounded but not 

 attenuated as in rotundus. 



GONEPLACIDAE 



Genus PSEUDORHOMBILA Milne Edwards 



Pseudorhombila xanthiformis, new species 

 Plate 24, Figs. 1-5 



Type: Female, holotype. Cat. No. 3810, Allan Hancock Foundation, 

 The University of Southern California, from north of Gorgona Island, 

 Colombia, 40-60 fathoms, mud and rock; February 24, 1938; collected 

 by Allan Hancock Expedition of 1938 at Velero Station 854-38. 



Measurements: Female holotype: length of carapace 15.1 mm., width 

 22.0 mm., of front 6.5 mm., of fronto-orbit 12.6 mm., length of cheliped 

 25.0 mm., of chela 14.7 mm., of major dactyl 8.0 mm. 



