Boone, Crustacea, Cruise of "Alva," 1931 139 



Distribution: Hawaiian Islands, "probably tbe same from Tu- 

 tuila, Samoa, and Straits of Balabac" (Dana). Hawaii: Waikiki 

 Beach, south coast of Molokai, 23 to 73 fms., Penguin Bank, 28 to 14 

 fms. ; vicinity of Kauai, 68 to 99 fms.; Modu Manu, 24 to 46 fms. 

 Society Islands, Ellice Islands, Paumotu Islands, atolls, and 22 to 25 

 fms. (Rathbun) ; Marquesas Islands, Society Islands and Samoa, 

 (Boone) ; Gatavake, Ohura, Rikitea, Mangareva Island, (Nobili) ; 

 Ceylon; Andaman Islands, (Alcock) ; Maldives: reef in Goidu, Fadi- 

 folu, atolls, dredged in South Nilander and Mahlos atolls in 22 to 25 

 fms., (Borradaile) ; Mauritius, (Alcock); Seychelles: Salomon, Car- 

 gados Carajos, Saya de Malha, 55 fms., Amirante, 29 to 80 fms., 

 Coetivy, by diver, 32 ft., (Rathbun). 



Material examined : Six male specimens, taken from coral reef at 

 Anaho Bay, Nuka Hiva, Marquesas Islands, South Pacific Ocean, 

 August 10, 1931, by the "Alva." Three males, three females, two 

 being ovigerous, taken on Venus Point Reef, Tahiti, Society Islands, 

 August 15, 1931. One male taken at Pago Pago, American Samoa 

 Islands, September 2, 1931. 



Technical description: All the "Alva" specimens are small, the 

 largest, a male, having the carapace 9 mm. wide and 6 mm. long, hex- 

 agonal, with the frontal border equal to half the total width of cara- 

 pace; with a distinct median emargination, the lobes being slightly 

 convex on either side of the median sulcus, and with their outer angles 

 set apart by a distinct notch from the orbital angle. The orbital mar- 

 gin is not circumscribed ; the anterolateral margins, which are shorter 

 than the postlateral margins, are cut into four teeth, in addition to the 

 orbital tooth. The first tooth is quite small, nearly obsolete, while the 

 second and third are conspicuously larger, the third being the largest 

 of the series and usually distinctly procurved. The fourth tooth is 

 quite small. The surface of the carapace is smooth with very moder- 

 ate convexity, none of the regions are delineated and there are no areo- 

 lations. However, the next to the largest specimen has on the outer 

 branchial region a small tubercle behind each the second and third 

 anterolateral teeth, but there are no grooves or wrinkles of the cara- 

 pace such as occur in C. niger (Ruppell). On the largest specimen 

 these tubercles are absent on the right side of the carapace and only 

 one occurs on the left side of the carapace and this one is faint. 



The chelipeds are markedly unequal, the merus in some specimens 

 being without a spine, but in most specimens having a spine on the 

 anterior margin, the carpus with a prominent tooth at the inner angle 



