THE SNAPPING SHRIMPS (ALPHEID^) OF THE DRY 

 TORTUGAS, FLORIDA. 



By Henri Coutiere, 



Of the Ecole Superieure de Pharmacie, Paris, France. 



The Alpheidse collected by Dr. J. F. McClendon at the Tortugas, 

 Florida, in the course of his study of the habits of crustaceans during 

 the summer of 1908, are referable to eight different forms, including 

 one new species and one new subspecies. They are as follows: 



ALPHEUS FORMOSUS Gibbes. 



ALPHEUS CRISTULIFRONS Rathbun. 



ALPHEUS ARMILLATUS H. Milne Edwards. 



This species, one of the most abundant and the most widely dis- 

 tributed on the American coast, very often accompanies A. hetero- 

 chsdis. It has nearly always been confused with that species, per- 

 haps by Say himself. So far as I know, the types of A. Tieteroehxlis 

 no longer exist, but those of A. armillatus H. Milne Edwards are in 

 the museum at Paris and permit the differentiation of the two forms 

 almost with certainty. 



A. Jieterocliselis has a rostrum with rounded borders, and the rostro- 

 orbital depressions are not definitely limited behind, but gradually 

 join the carapace. Furthermore, the small claw of the male is armed 

 with longitudinal crests furnished with hairs on the movable finger. 

 The claw suggests the beak of Balseniceps (the Whale-headed Stork 

 of Africa) , following the comparison of Hilgendorf . 



In A. armillatus the rostrum has the form of a sharp crest which 

 widens abruptly into a triangular space. The concave borders of 

 this triangle very distinctly limit the rostro-orbital depressions 

 behind and even slightly overhang them in the adult specimens. 

 Lastly the small claw of the male is never comparable to the beak of 

 Balseniceps. The specimen collected by Doctor McClendon is a 

 young male in which the typical form of the rostrum is little marked. 

 The hooks terminating the third, fourth, and fifth feet are also longer 

 than in the adult. 



Proceedings U. S. National Museum, Vol. 37— No. 1716. 



485 



