THE AMERICAN SPECIES OF SNAPPING SHRIMPS OF 

 THE GENUS SYNALPHEUS." 



By Henri Coutiere, 

 Of the Ecole Sup^rieiirc dc I'harmacie, Paris. 



HISTORY OF THE AMERICAN SPECIES OP^ THE GENUS. 



The nominal species of Synalpheus from the coasts of America at 

 the present time are eight in number, of Avhich one, Alpheus precox 

 of Herrick, is a nomen nudum. All of them appeared at ficst under 

 the generic name of Alpheus: A. Tnhius Say (1818), ^4. spinif^'ons 

 Milne Edwards (1837), A. tridentulatus Dana (1852), .1. saidcyi 

 Guerin (1856), A. leviusculus Lockington (1878), A. saulcyi longi- 

 carpus and A. saulcyi hrevicarpus Herrick (1891). 



These nominal species are so imperfectly diagnosed that I have 

 been able to retain the names of only three of them, Syncdpheus 

 minus (Say), S. hrevicarpus (Herrick), and S. longicarpus (Her- 

 rick). This list could have been augmented by Alpheus leviusculus 

 Lockington, had it not been necessary to change the name (it having 

 been preoccupied by Dana) to S. lockitigfoni. 



The A. spinifrons of Milne Edwards is from Chile. The type is 

 lost, and I have seen no form from that region which exactly corre- 

 sponds. Although Nicolet's drawing may be very imperfect with 

 regard to the cephalic appendages, yet the scaphocerite seems to be 

 much reduced, and this is confirmed by the text : " lamina basilar de 

 las antenas esternas muy pegueha, sin llegar con mucho a la estremi- 

 dad del pediinculo de estos organos." I do not believe that the 

 species, in view of this circumstance, can be placed elsewhere than in 

 the L^viMANUs group. The small claw, it is true, is described sim- 

 ply " con algunas pelos," but the plume of long hairs, so charac- 

 teristic of this claw in the group, could, in spite of its constancy, very 

 easily pass unnoticed. This plume has never before been described 

 or figured; but the unusual prevalence of the L.evimanus group on 

 the American coasts compels me to recognize the importance of this 

 curious, though apparently insignificant, character. 



Formerly, I identified Alpheus tridentidatus Dana with A. minus 

 Say, by reason of the short and broad form of the frontal teeth and 



" Translated from the French by Miss Mary J. Rathbuu. 



Proceedings U. S. National Museum, Vol. XXXVI— No. 1659. 

 Proc. N. M. vol. xxxvi — 09 1 



