I9I7-] 



S. Kemp : Notes on Crustacea Decapoda. 



265 



Rhynchoplax nasalis, sp. nov. 



The carapace is almost exactly circular and is nearly or quite 

 as broad as long, excluding the rostrum. The surface is sunken, 

 covered with hair, and with the grooves sharply defined. The 

 border is entire, upturned, and is continuous from side to side 

 across the base of the rostrum. 



The rostrum differs from that of all other species in the genus 

 in the suppression of the lateral processes; it consists merely of a 

 single horizontal plate, more than twice as long as wide, pointed 

 at the apex and bordered with hairs (text-fig. 12). 



H'iG. 12. — Rhynchoplax nasalis, sp, no\-, 



The basal segment of the antennular peduncle and the whole 

 of the eye are visible in dorsal view. There is no post-ocular tooth 

 and no trace of an inter- antennular septum. The epistome is of 

 moderate length. The external maxillipedes are similar to those 

 of the preceding species, but the merus is larger in proportion to 

 the ischium and, when normally folded, the stalk of the exognath 

 extends much beyond the distal end of the merus. 



The chelae are swollen in both sexes and are much stouter 

 than the walking legs ; they are only a trifle larger in the male 

 than in the female. The distal end of the lower border of the 

 merus ends in a stout tooth, but the segment is not otherwise 



