68 Bulletin Vanderbilt Marine Museum, Vol. VI 



Tahiti, Society Islands (Bate) ; Venus Point Reef , Tahiti (Boone) ; 

 Hao Island, Paumotu Archipelago (Nobili) ; Gambler Island 

 (Gruvel). 



Material examined: Four young specimens, from Venus 

 Point Reef, Tahiti, Society Islands, August 15, 1931. 



Technical description : The eyes are large, spherical and af- 

 ford only generic characters. 



The third pair of maxillipeds have a distinctive, short, tri- 

 angulate exopod. 



The legs are monodactyl and possess no specific characters, 

 except that the female has the fifth pair of legs modified. The 

 distal end of the propodus is produced at the inferior distal angle 

 into an oblique triangular process and immediately opposed to it 

 on the proximal outer lateral margin of the related dactyl there 

 is a similar obliquely placed acuminate triangle. 



The abdominal segments bear the important specific character 

 of possessing each a transverse groove that extends entirely across 

 the respective segment, terminating on either side near the base 

 of the epimera. 



The first pair of epimera is very acute, the second to fifth pairs 

 of epimera, inclusive, are also acute, and consist of the strong 

 curved tooth, formed by the production of the anterior margin ; 

 the second, third and fourth teeth of the second, third and fourth 

 epimera each has a denticle on the anterior margin, the posterior 

 margins of these teeth is each distinctly concave and terminates 

 on the postlateral angle in a small acute tooth ; the sixth epimeral 

 tooth is closely applied to the base of the uropoda. Each of the 

 epimera has a sharp oblique groove which arises near the inter- 

 locking "button" of the segment and extends down near the an- 

 terior border of the segment and thence curves backward almost, 

 but not quite, reaching the concave margin. The proximal portions 

 of the telson and uropoda are calcareous, this area of the telson 

 being definitely patterned and ornamented with a few denticles ; 

 the distal portion of the rhipidura is flexible, membranaceous, and 

 ornamented by fine longitudinal grooving. 



This species is one of the most gloriously colored and highly 

 ornamented members of the genus. The pair of rostral horns are 

 strongly procurved, extending above and beyond the eyes. The 

 postorbital and antennal spines are strong and forward protru- 



