KINGSLEY ON THE GENUS ALPHEUS. 193 



Acajutla, Central America, and Panama {F. R. Bradley). Three speci- 

 mens from the latter locality give the following measurements : — 



Alpheus sulcatus Kingsley. 



Carapax smooth ; rostrum short, extending very slightly beyond the 

 vaults over the eyes, which are produced forward, though they can 

 scarcely be called spiniform ; sides of the rostrum with long hairs. 

 Basal spine of antennulse reaching to the, second joint; third joint the 

 shortest. Inner branch of flagella a third longer than the carapax ; 

 outer about half as long as inner. A small spine on the basal joint of 

 antennse beneath; antennal scale equalling antennular peduncle, regu- 

 larly tapering; flagellum nearly as long as the body. External maxilli- 

 peds slender, extending beyond antennal scale, the distal joint being 

 ciliated. Meros of larger cheliped triangular; no spine above; hand 

 ovate-compressed, with a few scattered hairs ; a slight sulcus on the 

 upper margin of the palm ; a furrow on the outer, and a similar one on 

 the inner surface of the hand, running back from the articulation of the 

 dactylus to about the middle of the palm ; a slight constriction on the 

 under margin ; thumb distorted, a furrow on the outer surface parallel 

 with the occludent margin ; dactylus about a third as long as propodus, 

 extending beyond the thumb ; a tooth on the inner margin, as in A. 

 heterochelis. Carpus of the second pair five-jointed; first joint as long 

 as the next two; second a half longer than third; third and fourth' 

 equal; fifth as long as second. Telson tapering- truncate. 



Of this form I have seen but two imperfect specimens; one from the 

 Bay of Panama, and the other from Zorritas, Peru {F. H. Bradley), 

 which give respectively the following measurements: — 



Length of hody. Carapax. Larger hand. 

 35;0mm 11. 8"""* 1.5.5™'" 



23.3 8.0 10.3 



Alpheus ploridanus Kingsley. 



Carapax smooth, somewhat compressed ; rostrum short, acute, the 

 carina running back nearly to the middle of the carapax. Basal spine 

 of antennulse extending but slightly beyond the rostrum. Second joint 

 of antennular peduncle three times as long as the last joint; outer 

 branch of flagella stout, a little longer than the peduncle ; inner brancli 

 slender, twice as long as the outer. Antennal scale as long as peduncle 

 of inner antennse, and shaped as in A. heterochelis ; flagellum a half 

 longer than the body. Meros of first pair trigonal, the inner inferior 

 edge bearing small spines. Hands unequal, the larger compressed, one 

 and a half times as long as the carapax; fingers equal, pointed, com- 

 pletely closing, occupying about two-fifths the length of the hand. 

 Bull. iv. No. 1—13 



