Boone, Crustacea, Cruise of "Alva" 1931 29 



(Hilgendorf) ; Southport, Queensland (Boone) ; Australia (White, 

 Miers) ; Amboina Island, Moluccas (Ortmann, Hilgendorf, Zehnt- 

 ner) ; British New Guinea (Borradaile) ; Anchorites Islands (Hil- 

 gendorf) ; New Britain, Conflict Islands (Borradaile) ; New Ire- 

 land (Hilgendorf) ; Lifu, Loyalty Islands, Rotuma (Borradaile) ; 

 Fiji Islands (Dana) ; Society Islands, Tahiti (Heller) ; Papeete, 

 Tahiti (Henderson) ; Venus Point Reef, Tahiti (Boone) ; Sand- 

 wich Islands (Randall) ; Marokau, Fakahina, South Marutea, Hao 

 Island, Paumotu Archipelago, Vaiatu Kene, Mangareva (Nobili). 



Material examined : One large specimen, Southport, Queens- 

 land, September 24, 1931. One specimen, Venus Point Reef, Tahiti, 

 Society Islands, August 15, 1931, carcinocaecum, Nerita species. 



Technical description: Precervical portion of carapace 

 squarish, wide as long, frontal margin truncate, except for the 

 paired submedian triangulate points, one each between the base 

 of the eye and the external antennae. Lateral margins rough with 

 denticles and tufts of coarse setae. A wide, U-shaped, linear 

 groove is anterior to the posterior margin. The postcervical region 

 is leathery with longitudinal striations. The abdomen has three 

 transverse, leathery bands dorsally; the pretelsonic and telsonic 

 segments are calcareous, the left side and left uropod being much 

 the larger. 



The ocular scales are triangulate with the apices directed 

 inward. 



The eyestalks are thick, their length including the cornea, equal 

 to one-half of the frontal margin, the width of the stalk being 

 about one-half of the total length; dorsally having a rounded 

 process extended upon the cornea; the latter is terminal, hemi- 

 spherical, black, a trifle wider than the stalk. 



The antennulae are slender, exceeding the length of the eye by 

 about one-half of the length of the distal peduncular article and 

 flagellum. 



The antennae have the basal article squarish, with the external 

 distal angle acute, the acicule narrow, tapered, triangulate, the 

 tip not quite reaching the base of the cornea; the second joint is 

 small, semiconcealed beneath the acicule ; the third article is slen- 

 der, elongate, extending as far as does the cornea ; the flagellum 

 is multiarticulate, about one and one-half times as long as the 

 entire carapace. 



