38 Memoirs of the Indian Museum. [Voi,. IV, 



the anterior margin. The dactylus bears six teeth including the terminal one ; the 

 outer margin is convex and bears an acute lobe at the base. 



The lateral process of the fifth thoracic somite is, in the Indian specimens, rather 

 longer than is indicated in Brooks' figure ; it is almost straight and trends obliquely 

 outwards and forwards. The pair of inferior spines are sharp. The lateral margins 

 of the two succeeding somites are broadly rounded, those of the eighth somite are 

 lobed anteriorly. The intermediate carinae of the free thoracic somites are distinct, 

 but the submedians are either wholly absent or are represented only by obsolete traces 

 on the last two somites. 



There are no submedian carinae on the first three abdominal segments, obsolescent 

 indications of them may, however, be found on the fourth and fifth somites ; on the 

 sixth they are invariably present and well developed. The intermediate, lateral and 

 marginal carinae are, as is usual, quite distinct. The following abdominal carinae end 

 in spines : — . 



Carinae Abdominal somites. 



Submedian . . . . . . 6. 



Intermediate .. .. .. (3)4,5,6. 



Lateral . . ... . . 3, 4, 5, 6. 



Marginal .. .. . (1) (2) 3, 4, 5. 



These figures refer to the Indian specimens ; Brooks remarks that in the type 

 spines are found only on the last somite. 



The dorsal surface of the telson is finely rugose and, on either side of the median 

 crest, is obscurely marked with faint parallel furrows. The marginal teeth are well 

 developed and there are one to three ' submedian denticles, six to eight intermediate 

 and one lateral. In the Indian examples the outermost median denticle is borne 

 on the inner face of the intermediate tooth and projects distally beyond its fellows. 

 There is no praelateral denticle. The post- anal carina is short but distinct. 



The bifurcate process of the peduncular segment of the uropods bears six to eleven 

 sharp teeth on its inner margin and on the outer face of the longer spine there is a large 

 and very conspicuous rounded lobe (fig. 24). 



The two largest specimens examined are males ; but, except for a feeble swelling 

 at the base of each intermediate marginal denticle of the telson, no distinctive sexual 

 modifications are to be found. 



The Indian examples of 5. lata differ from Brooks' account in the possession of a 

 dorsal spine at the distal end of the peduncle of the uropods and in a few other details 

 noticed above, the most important being the greater abundance of spines on the 

 abdominal somites. Should the distinctions prove constant it may be necessary to 

 separate specimens from the Bay of Bengal under a distinct subspecific name. 



Spirit specimens exhibit no characteristic colouring. 



The three examples in the collection are registered as follows : — 



^—^ Gulf of Martaban, Burma; 53 fms., 



I4°38'i2" N., 96°24'3o" E. 'Investigator.' 1 <? , 2 2 , 64 — 76 mm. 



' Two or three in the Indian examples, a single broad lobe in the types. 



