148 RATHBUN 



as body. The dactylus of the external maxillipeds is subspatulate, fully 

 twice as long as broad. The chelae of the first pair of feet are narrow 

 and elongate, as in the succeeding pairs. 



Exopodites of first abdominal appendages not so long as the carapace ; 

 between the bases of these appendages is a sharp spine, equally devel- 

 oped in both sexes. The thelycum consists of a horizontal convex sub- 

 triangular plate or tubercle, placed between the third pair of legs, 

 followed by two transverse plates between the fourth and fifth pairs. The 

 ><^^N anterior of these two plates is subquadrilateral, 

 / "~~~T\ narrowest in front ; the posterior one is somewhat 

 w fan-shaped, narrow behind, its anterior margin 

 ^1 rounding and with a blunt median point. The 



I *> andricum or petasma consists of a pair of small 



leaves not in contact, each of which is attached at 



FIG. 89. Gennadas borealis. . . 



t . station 3783. a. Petasma its proximal end. At extremities of distal margin 



(X 6). b. Foot of first pair 



(X4)- are two lobes or teeth, the outer one of which is 



curved. The inner portion is partially folded to form an irregular longi- 

 tudinal plait. The sixth abdominal somite is carinate ; it is more than 

 twice as long as the fifth. The telson has a small lateral spine at its 

 posterior fourth, two spines at the tip. The caudal swimmerets are 

 broken in all our specimens. 



Dimensions. Male, length of carapace and rostrum 13.6 mm., length 

 of abdomen on middle line 29 mm. Female, length of carapace and 

 rostrum 18 mm., length of abdomen on middle line 37 mm. 



Distribution. North of Rat Islands, Aleutians, 850 fathoms (Alba- 

 tross station 3784), 2 $ ; off Copper Island, Kamchatka, 1567 fathoms, 

 station 3783 (type locality), 13,2$. 



Very near G. parvus Bate, but differs in the longer rostrum, the 

 presence of a lateral spine on the telson, the greater length of the anten- 

 nal scale, the elongated chelae of the first pair of feet, and the different 

 form of the thelycum and andricum. 



A specimen of Gennadas was dredged by the Albatross off San Diego 

 in 417 fathoms, station 2928, but it is so badly mutilated that it is im- 

 possible to say whether it is the same species as the above or not. 



Family PALINURIDJE. 



Genus Panulirus White. 



PANULIRUS INTERRUPTUS (Randall). 



Distribution. Southern California to Mexico. In the National Mu- 

 seum are specimens ranging from Santa Barbara, California, to Rosalia 

 Bay, Lower California. 



