556 THE VOYAGE OF H.M.S. CHALLENGER. 



Habitat. — Honolulu, reefs. One specimen ; male. 



Dana obtained his specimens from the Sandwich Islands, and also from the Fiji 

 Group, and Heller records it from the Nicobar Islands, Sydney and Tahiti. 



Observations. — This species is undoubtedly Alpheus Isevis, Randall, as figured and 

 described by Dana. In our specimen the left hand is broken off, but one found in the 

 bottle agrees with the figure in Dana's plates, and if it belongs to our specimen the 

 left hand is rather larger than the right, being, 14 mm. long, while the right is 13 mm.; 

 in width the right is 5 mm., and the left 7 mm. The detached limb, although it has 

 the character of being from the left side, and corresponds with Dana's figure, may be 

 that of a second specimen, but as there was no other in the bottle to which it could 

 belong, I believe it to have dropped from this one, and so describe it, having, however, 

 figured it detached (fig. 3£). Each of them has the upper surface covered with small 

 spots, and a number of short hairs. 



On the branchial region of the carapace, corresponding with the upper extremity 

 of the branchial chamber, a series of capillary vessels are seen within a circular margin 

 of transparent tissue (fig. 3c). 



Alphens prolificus, n. sp. (PI. XCIX. fig. 4). 



Carapace two-thirds of the length of the pleon. The rostrum narrow. The orbital 

 lobes pointed, broad, and nearly equal in length to the rostrum. 



First pair of antennas having the second joint of the peduncle shorter than the first, 

 the third subequal with the second. Stylocerite a little longer than the first joint, 

 fiagella subequal and about as long as the carapace. 



Second pair of antennas as long as the animal, peduncle longer than that of the first 

 pair, basal tooth as long as the stylocerite and nearly half as long as the scaphocerite, 

 which is subequal with the peduncle. 



First pair of pereiopoda lost. Second slender, having the carpos five-articulate, the 

 first articulus being longer than the four following ones. Third and fourth pairs robust, 

 meros broad, compressed, without distal tooth ; carpos anteriorly produced on the upper 

 distal margin ; propodos curved, furnished with spines on the posterior margin ; dactylos 

 stout, bluntly pointed, with a small secondary unguis on the outer surface (fig. 4m). 



The pleopoda are broad and foliaceous. 



Telson broad, smooth, furnished with two spinules on the dorso-lateral surface, 

 tapering and rounded at the extremity. 



Length, entire, . . . . . .20 mm. (0'8 in.). 



„ of carapace, . . , . . 8 ,, 



Depth of carapace, . . . . . 5 '5 „ 



Length of pleon, . . . . . 12 „ 



