i8o Memoirs of the Indian Museum. [Vol. IV, 



5. The lateral margin of the sixth thoracic somite is more sharply rounded and 



that of the seventh is less clearly truncate. 



6. The dorsal pits and lateral sculpture on the first five abdominal somites are 



wholly obsolete. 



7. The boss-like elevations on the sixth somite and telson exhibit no trace of the 



clothing of setae found in the preceding species, and the rest of the surface 

 shows only the feeblest indication of pitting and reticulation. 



8. The three bosses on the telson are less elevated and are separated only by a 



shallow groove ; in consequence, they appear to be partially connected with 

 one another anteriorly. The median fissure in the distal part is similar to 

 that in G. pulchellus and is cut right through the telson ; but the margins 

 touch one another throughout all, or almost all, their length. The four lobes 

 on either side are separated by incisions that are much shallower than in the 

 preceding species. On the dorsal surface they are continued forwards as 

 grooves almost halfway to the base of the lateral bosses, but they are not cut 

 right through the telson for this distance and are not widened proximally as 

 in G. pulchellus. 



9. The inner spine of the process from basal segment of the uropods is not more 



than half the length of the outer. The inner uropod is broader in proportion 

 to its length, and the outer margin of the proximal segment of the exopod 

 bears from ten to twelve movable spines. 



No characteristic colouration can be found in spirit specimens. 



The forty-seven specimens in the Indian Museum were found at the following 

 localities : — 



~ Andamans. J. Wood-Mason. 15 tf , 19 9 , 11-39 mm - 



TYPES. 



~ Andamans. J. Wood-Mason. 1 $ , 32 mm. 



~ Andamans, 20 fathoms. ' Investigator.' 1 $ , 16 mm. 



~^ Port Blair, Andamans. G. H. Booley. 2 & , 19 and 27 mm. 



^ Cheduba, Arakan Coast, 7 fathoms. 'Investigator.' 4 tf , 4 ? , 16-40 mm. 



1J P Southern portion of Malacca Strs. ' Sherard Osburn.' 1 9 , 20 mm. 



14. Gonodactylus trispinosus t Dana. 



1847. Gonodactylus trispinosus, White, List Crust. Brit. Mus., p. 85 (partim, nom. nui.). 

 1852. Gonodactylus trispinosus, Dana, 1 U.S. Explor. Exped., Crust., p. 623. 



1 In this work Dana attributes the species to White, and cites as his authority pi. V of the Voyage of 

 the 'Erebus ' and ' Terror,' a work that, in its completed form, was only issued twenty-four years sub- 

 sequently (1874). In this volume, moreover, the text is written by Miers ; there are only four plates, and 

 there is no account or figure of G. trispinosus. It seems, however, from Miers' introductory statement that 

 the plates were issued under White's supervision many years previously, and copies must have been in Dana s 

 possession when writing in 1852. Of the absence of plate V in the completed account, no explanation is 

 forthcoming. 



