EEPORT ON THE CEUSTACEA MACRUEA. 571 



and daetylos united, is long, tapering, tipped with long hairs, and fringed, particularly 

 on the lower side, with numerous short ones, as also is the carpos and meros. 



The first pair of pereiopoda (k) is unequal on the two sides, and has sometimes one 

 sometimes the other hand the larger. In the typical specimen, that upon the right side 

 is the smaller and more normal in form ; it is moderately large and well developed; the 

 propodos is long, and has the pollex as long as the daetylos and a little more slender, 

 and both are inwardly curved at the apex, and have the inner margin fringed with 

 hairs. The carpos is short, narrow and triangular ; the meros is cupped at the carpal 

 extremity, and articulates with the carpos at the inferior angle only, the upper angle 

 being produced to a point and tipped with a bunch of hairs ; the meros is long and the 

 ischium short, as are also the basal joints. The coxa carries a short rudimentary 

 mastigobranchial process. The hand upon the left side differs from that on the right 

 in having the meros larger, and the antero-superior process more distinctly developed 

 and hollowed to receive the posterior lobe of the carpos ; the carpos is short and 

 triangular; the propodos is unusually large, ovate, broader at the carpal extremity than 

 at the dactyloid infero-anterior angle, which is produced in an obtuse pollex ; the 

 daetylos is broad, arcuate, and diagonally articulated with the propodos on the outer 

 side. The second pair of pereiopoda is long and slender, with the hand minute and oval, 

 the carpos five-articulate, the meros slender and the ischium robust. The third and 

 fourth pairs of pereiopoda are stout and well developed, with the posterior margin 

 serrate ; the ischium is short, the meros and carpos long, the daetylos short and single- 

 pointed. The fifth or posterior pair of pereiopoda resembles the preceding, but is 

 generally more slender, and has the ischium proportionately longer, and the posterior 

 margin smooth. 



The pleopoda are long and flexible. The first pair (jp) in both sexes carries one 

 normally developed, and one rudimentary branch. The second (q) and following pairs 

 are furnished with a long stylaniblys, and the terminal pair, which forms the outer plates 

 of the rhipidura (vzv), is armed at the outer distal angle with two strong divergent 

 teeth, and between them two long movable spines, the plate having a well-marked 

 diaaresis. The distal margin of the outer as well as of the inner plate is fringed with a 

 series of small teeth and fine hairs, of which those on the outer margin of the inner 

 plate are the larger. 



The telson is shorter than the lateral plates, and elongo-quadrate in general form ; 

 the posterior margin is slightly convex, fringed with long hairs, and armed at each angle 

 with a sharp tooth and a small spine. The lateral margins are smooth but on each side 

 of the median line is a strong ridge armed with two short spines, one distantly behind 

 the other. 



Our specimens appear to correspond more nearly with Alpheus diversimanus than 

 with Atyheus villosus, as they are described by Mdne-Edwards, and as they are 



