160 Bulletin, Vanderhilt Marine Museum, Vol. II 



five-segmented, the third, fourth and fifth segments being completely 

 fused, but with a carina marking the union of the third and fourth 

 segments ; the second and third segments each have a prominent me- 

 dian transverse carina. 



The antennulae have the basal segment narrow and wide, the free 

 articles, slender, cylindrical, folding transversely. 



The antennae have the basal peduncular joint rounded into knob 

 distally which is appressed to the orbit and armed subdistally with a 

 tooth, the free articles are small ; the flagellum long, extending to the 

 tip of the seventh lateral tooth. 



The external maxillipeds have the ischium rectangular, the merus 

 squarish, three-fifths as long as the ischium and slightly excavate for 

 the reception of the palp. 



The chelipeds are highly ornamented, the merus having five, strong, 

 acute teeth on the inner lateral margin ; the carpus with a prominent 

 tooth at the inner angle, a minute one at the outer angle, three inter- 

 rupted carinae on the outer surface, the median of which bears a dis- 

 tal and a subdistal tooth ; there is also a prominent tooth proximally 

 on the propodus, at the median tip of the carpus; the propodus is 

 robust, slightly longer than the fingers and bears on its outer face four 

 beautiful beaded, heavy carinae, the lowest of which is continuous to 

 the tip of the lower finger; the fourth carina, just below the upper 

 margin terminates in an acute subdistal tooth. 



The upper margin is beaded and bears two acute teeth, one distal 

 and one midway its length; the fingers are slender, grooved and ir- 

 regularly dentate; the tips are a darker color than the rest of the 

 fingers. 



The ambulatories are slender, with long, grooved dactyli. 



The natatory leg has the merus elongate, three carinae on the upper 

 surface, the outer of which forms the posterior lateral margin and ter- 

 minates in a subdistal tooth ; the propodus is as large as the dactyl and 

 subovate ; the dactyl is oval. 



Synonymy. — Neptunus sulcatus A. Milne Edwards. Miss. Sci. au 

 Mex. et dans I'Amerique Centrale, t. V, p. 26, pi. 39, fig. 3, 1881. 

 — A. Milne Edwards and Bouvier, Mem. Mus. Comp. ZooL, vol. 

 47, p. 311, 1923. 



Portunus (Portunus) sulcatus M. J. Rathbun, Bull. U. S. Fish. 

 Comm., vol. 20, part 2, p. 45, 1901 ; State Univ. Iowa Studies Nat. 

 Hist., vol. 9, No. 5, p. 67, 1921. 



