558 



THE VOYAGE OF H.M.S. CHALLENGES. 



other small teeth or points, and in front of them a sulcus that unites faintly with the 

 one on the upper side. The pollex is sharp pointed and curved upwards towards the 

 anterior extremity ; the dactylos is broad, arcuate, obtuse at the point and furnished 

 posteriorly with a large tubercle, that corresponds with a deep notch in the 

 posterior portion of the pollex. The second pair of pereiopoda has the carpos six- 

 articulate. The three posterior pairs are subequal, the last being but slightly more 

 slender than the preceding two pairs, and has the propodos fringed with small spines. 



The pleopoda are long and slender, and carry in the female a large number of small 

 round ova. 



The posterior pair of pleopoda forms the lateral plates of the rhipidura. The outer 

 margin of the outer plate is rigid, and terminates in two small teeth, the space between 

 them being occupied by a spine ; the diaeresis is well defined, and the terminal portion of 

 the plate is broad and short ; the inner plate is terminally rounded, and both are distally 

 fringed with long plumose hairs. 



The telson is long and tapers to the distal extremity, it is armed on the dorsal surface 

 with two short spines on each side of the median line ; the terminal margin is convex, 

 armed at each corner with a small spine and fringed with long and ciliated hairs. 



Habitat. — Off Bahia ; in from 7 to 20 fathoms. One specimen ; female, laden with 



ova. 



Al-plieus minus, Say (PL C. fig. 2). 



Alpheus minus, Say, Journ. Acad. Nat. Sci. Philad., vol. i. p. 245, 1818. 

 ,, „ Milne-Edwards, Hist. Nat. Crust., torn. ii. p. 356. 



„ Kingsley, Bull. U.S. Geol. Survey, p. 190, 1878. 



Carapace anteriorly produced to a sharp pointed rostrum that reaches to about the 

 extremity of the first joint of the peduncle of the first pair of antennas. Orbital 

 margin anteriorly produced to a point subequal with the rostrum. 



First pair of antennas rather longer than the carapace. 



