18 



peduncle : the rostrum is produced backwards as a distinct carina only in the 

 anterior half of the carapace. The cervical groove and its posterior branch are 

 deep-cut on the sides of the carapace : a sinuous longitudinal ridge is very 

 prominent on either epibranchial region. 



The abdomen begins to be indistinctly carinate, in the mid-dorsal line, at 

 the after end of the 3rd tergum, but the carina becomes very sharp on the 4th, 

 6th, and 6th terga and ends in a spine. The 6th abdominal somite is consid- 

 erably less than twice the length of the 5th. The telson is a trifle longer than 

 the endopodite of the caudal swimmeret : it is armed on either side with 4 spines, 

 the last of which is fixed. 



Eyes large. In the female the antennular flagella are about equal and are 

 a little longer than their peduncle : in the male the inner flagellum is about as 

 long as its peduncle and very much shorter than the outer flagellum. Moreover 

 in the male the basal end of the inner flagellum is bent downwards to form a 

 rigid semicircular hoop twisted inwards at its far end where the hoop ends in a 

 strong recurved tooth. In both sexes the antennal scale is about as long as the 

 rostrum. 



The 2nd joint of the palp (endopodite) of the mandible is very thin, 

 glabrous, and about as broad as long. 



There is a spine at the far end of the ventral border of the basis and 

 ischium of the 1st pair of thoracic legs, and in the female a spine also on the 

 basis of the 2nd pair. 



The " thelycum " is trilobed with the anterior (median) lobe nearly semi- 

 circular: the space between the lateral lobes is excavated and is bounded 

 posteriorly by a tubercle. 



The " andricum " of the 1st pair of abdominal appendages consists of a 

 pair of equal leaves, which simply form a canal by their interlocking, and are 

 not mutually involuted as they are in P. coniger. 



The rostrum and carapace of the largest female are 52 millim., the extended 

 abdomen is 79 millim., measured in the mid-dorsal line. 



Not uncommon in the Bay of Bengal, off the Malabar coast, at 145 to -~2> > 

 fathoms : also at the northern end of the Andaman Sea, in 370-419 fathoms. 



T j -v- 6730-6731 9131-9180 2589-2595 



9 10 



3. Peneas (Parapeneusj investigator**, Anderson. 



Porapeneus invettigatorit, Alcock and Anderson, Ann. Mag. Xat. Hist., April 1899, p. 279. 



Parapeneiu fitaunu, Alcockand Anderson (ne.Spence Bate), Journ. As. Soc. Beug. Vol. LXIII.pU2, 1894, p. lit. 



ILLCSTKATIOKS OF THE ZOOLOGY OF THE INVESTIGATOR, CBCSTACEA, PLATE XLI. FIGS. 1, la-b. 



Glabrous, polished. Rostrum a little convex dorsally, its dorsal border with 

 6 or 7 teeth not including one on its gastric carina : in the female its free porti< m 



