Boone, Crustacea, Cruise of "Alva," 1931 147 



ama, also Colon, East Panama, (Finnegan) ; Rotuma; Funafuti, (Bor- 

 radaile) ; Kamaka, (Nobili) ; Savaii, (Pesta) ; Cocos-Keeling Atoll, 

 (Caiman) ; Male, Maldives, Minikoi, (Borradaile) ; Andamans, Mek- 

 ran (Baluchistan) coast, Laccadvies, Bombay, Aden, Samoa, Bantam, 

 (Alcock) ; Red Sea, (Nobili) ; lagoon, Diego Garcia, Seychelles, Coe- 

 tivy Island, (Rathbun) ; Bonin Islands, (Balss). 



Material examined: two males and one ovigerous female, taken 

 on the reef at Apia, Samoa, September, 5, 1931, by the "Alva." One 

 smaller male, one larger female from the same locality. 



Technical, description : Carapace oval, one and one-third times as 

 wide as long, depressed, flattish except the finely granular, deflexed 

 frontal-orbital region; the regions of the carapace are not delineated 

 except a slight urogastric line. The frontal margin is deflexed, cut 

 into two shallow, widely rounded submedian lobes, which are distinct 

 from the bluntly triangular outer lobes, which latter are separated 

 from the rounded superior inner orbital tooth by a rounded sinus. The 

 orbital border is smooth, slightly thickened, unbroken; the inferior 

 orbital tooth is thickened almost right-angled, not meeting the superior 

 tooth. The anterolateral border is widely rounded, arched, obscurely 

 cut into four very shallow lobes, tlie first and second lobes being 

 rounded and nearly confluent. The sidewalls of the carapace are 

 smooth, the buccal cavern is definitely narrower anteriorly, than poste- 

 riorly. The male belt has seven segments. The external maxillipeds 

 are smooth except for a longitudinal groove on the ischium. The an- 

 terior border of the merus is notched to complete the formation of an 

 expiratory aperture, in conjunction with the sharply defined crests of 

 the endostome. 



The antennules fold almost transversely, the median septum is 

 firm, and well developed. 



The antennae have the basal joint short; the second peduncular 

 joint shorter, cylindrical, but touching the frontal margin. The flagel- 

 lum very slender, not quite equal in length to the long diameter of the 

 orbit, and situated in the angle between the front and the orbital wall. 

 The chelipeds are large and unequal in both sexes, but are especially 

 massive in the male, smooth to the unaided eye, but under the micro- 

 scope showing rough pittings on the palm ; the carpus is convex on the 

 upper and outer surfaces, with a double tooth on the inner angle ; the 

 palm is massive, the fingers, slender, curved, in the female nearly meet- 

 ing along the cutting edge and bearing several teeth on the lower 

 finger ; on the male the fingers are widely gaping, meeting only at the 



