319 



d, Rostral carina, behind the median tubercle, continued in a 

 straight, obtuse crest, bounded on either side by a shallovv 

 groove or depression that ends abruptly at the posterior 



extremity of the crest praedator de Man 



c„ No pointed tooth on either side of the rostral carina, at the base 

 of the eye-hoods. 

 d x Frontal margin at either side with a slender spine. 



c\ Rostral carina armed with two spines, situated behind one 

 another, rostral carina prominent, reaching to the posterior 



third of the carapace cristatus Cout. 



(H. COUTIÈRE, in: Buil. Mus. Paris, 1897, N° 7, p. 303). 



e„ Rostral carina little prominent, without the spines characteristic 

 of A. cristatus, but with a minute tubercle, just behind the 

 level of the base of the eye-hoods. Midway between this 

 tubercle and the frontal margin on either side a lamellar crest 



with rather sharp edge runs obliquely backward .... bicostatus de Man 

 d s No spine on frontal margin at either side of the rostrum. 



e l Orbital hoods not regularly rounded; frontal margin with a 



prominence at either side of the rostrum; rostrum arising 



from a broad flattened base between the orbital hoods, the 



marijins of which base are concave. 



f x The flattened base from which the rostrum arises, is distinctly 



carinate, with a minute tubercle posteriorly; a broad arcuate 



and setiferous prominence between the obtuse tips of the 



eye-hoods and the rostrum insignis Heller 



f 2 The flattened base from which the rostrum arises, not carinate ; 



a very small, acute prominence at either side of the rostrum, diadema Dana 

 (J. D. DANA, U.S. Explor. Exp. Crustacea, p. 555, PI. 35, fig. 7). 



e„ Orbital hoods rounded anteriorly, frontal margin without a 

 prominence at either side of the rostrum. 

 ƒ, Rostrum lanceolate, as in A. gracilipes, the margins over- 

 hanging the rostro-orbital furrows. Dactylus of small chela 



of the male "Balaeniceps"-shaped Percyi Cout. 



(H. COUTIÈRE, in: Buil. Soc. Philom. Paris, 1908, p. 21). 



f„ Interorbital carina rather sharp anteriorly, obtuse posteriorly. 

 Second legs more slender than those of A. Miersi, 2 nd 

 carpal segment one and a half as long as the i st and 8- 

 times as long as thick ; 4 th segment one and a half as long 

 as the 5 th . Merus of 3 sd legs 5-times longer than wide, 

 armed, as in A. Lanceloti, with 4 movable spinules on the 



posterior margin, the apical tooth rather small .... Philoctetcs de Man 



187 



