358 DR. W. T. CALMAN ON NEW OR RARE 



them in the mid-dorsal line. There are a few scattered setae on the surface of the 

 carapace. 



The first leg-bearing somite is represented only by the pleural plates. The remaining 

 thoracic somites have the pleural plates .expanded and rounded. 



The abdomen is shorter than the cephalothoracic region ; the fifth abdominal somite is 

 barely twice as long as deep, and less than one-third longer than the preceding somite. 



The antennule has the third segment of tlie peduncle shorter than the second and, 

 together with it, a little shorter than the first. 



The third maxillipeds have no exopods ; the basis is less than one-third of the total 

 length of the limb ; the distal segments, especially the carpus and propodus, are very 

 stout and only slightly fiattened. 



The first legs have well-developed exopods ; the basis is about two-sevenths of the 

 total length of the limb ; the distal segments, especially the carpus and propodus, are 

 expanded and flattened. 



The second legs have well-developed exopods ; the basis is inflated and is about 

 equal to the remaining segments togetlier ; the distal segments are broad, the carpus 

 is distinctly longer than the merus, and the dactylus is only a little longer than the 

 propodus. 



The remaining legs do not differ greatly in length. The last pair are about two- 

 fifths of the total length of the body ; the basis is more than one-fourth of the length 

 of the limb, the carpus is about twice as long as the merus and a little shorter than 

 the propodus. 



The uropods have the peduncle nearly two-thirds as long as the last somite. The 

 eudopod is about twice as long as the peduncle, with a stout terminal spine of more 

 than half its length, and with three small spines on its inner edge. The exopod is 

 about one-fifth as long as the endopod, with a slender terminal spine which reaches 

 nearly to the end of the latter. 



Remarks.— A.'^dirt from the possession of exopods on the first and second pairs of 

 legs this species resembles the preceding somewhat closely, especially in the relative 

 length and proportions of the posterior legs and of the uropods. There are, however, 

 small but constant differences in the form of the carapace, which has the branchial 

 regions less inflated and the dorsal surface less arched; in the stoutness of the distal 

 segments of the third maxillipeds and first pair of legs ; and some small differences of 

 proportion noted in the description above. It has already been mentioned as a 

 possibility that this species may represent only a variation or a phase of development 

 of N. reptans, but I do not think that this is probable. 



Occurrence. — Gulf of Siam, " Koh Kahdat, about 1 fathom, coral, 1/2/00," 

 "Koh Chang, 1 fathom, coral, 1/3/00." Th. Mortensen Coll., Copenhagen Museum. 

 Co-types in British Museum. 



