130 BULLETIN OF THE 



nine small, slender, laciniated teeth, progressively diminishing in size for- 

 wards ; posterior tooth only one third the size of the large branchial spine 

 or tooth, which is the largest on the margin of the carapax. There is a 

 prominent tubercle at the summit of the branchial region. Rostrum of 

 moderate size, pointing obliquely downward and forward, and bearing a 

 tooth on each side near the base, and a smaller one near the tip. At the 

 basal tooth the rostrum is abruptly contracted more than one half in 

 width. Chelipeds rather long ; margins armed with laciniated teeth ; 

 meros convex, with the upper surface granulated and tuberculated, the 

 largest tubercles, those along the middle, being subspiniform ; carpus with 

 five large and several small spiniform tubercles above and on the outer 

 side. Upper surface of hand with only two or three tubercles about 

 the middle ; teeth of the margins larger and more triangular than those 

 of the margins of the meros ; those of the inner broader than those of 

 the outer margin, particularly those toward the fingers, which are not, like 

 those toward the carpus, separated by intervals ; inner margin with eight 

 large and three small teeth ; outer one with four large and six small teeth. 

 Lower surface of hand punctate, with a regular median row of tubercles. 

 Ambulatory feet somewhat compressed ; meros-joint spinulose on both 

 upper and lower edge. The ridges of the abdomen, sternum, and outer 

 maxillipeds are tuberculated. 



Dimensions of a male : Length of carapax, 0.47 ; breadth, lateral teeth 

 included, 0.52 inch ; proportion of length to breadth, 1 : 1.106 ; length of 

 meros-joint of chelipeds, 0.3 7 inch. 



Off Conch Reef, March 21, 1869. 



Off French Reef, March 21, 1869. 



Off American Shoal, May 6, 1868. 



Off Conch Reef, May 11, 1869. 



Lambrus frater cuius nov. sp. 



Nearly allied to L. Pourtalesii, but differing as follows : The carapax is 

 narrower, the proportion of length to breadth being 1 : 1.04 even in the 

 female, while in the male it is longer than broad. The depressions between 

 the branchial and the gastric and hepatic regions are much deeper. In 

 the female the tubercles of the carapax and the teeth of the margins are 

 less spiniform and generally smaller ; the tubercles of the branchial and 

 gastric regions are indeed sometimes obsolete or nearly so. In the only 

 nude specimen at hand, the median tubercle of the gastric and that of the 

 cardiac region are much taller than in L. Pourtalesii. The rostrum is also 

 longer than in that species, with the narrowed extremity much more 

 slender, and the basal teeth more prominent ; there is also a small slender 



Cast No. 1. 



40 fathoms, 



Cast No. 2. 



45 " 



Cast No. 9. 



100 " 



Cast No. 6. 



117 " 



