19 



is less than half the length of the rest of the carapace, measured in the mid- 

 dorsal line, and its tip reaches a little beyond the basal joint of the antennular 

 peduncle, but in the male it does not quite reach the end of that joint : the 

 rostrum is produced backwards as a carina for more than two-thirds the length 

 of the carapace. 



The grooves that join the hepatic with the antennal and branchiostegal 

 spines are very distinct : a fine fissure runs along the whole length of the 

 carapace on either side, from a point just inside the antennal spine to the 

 posterior border : an even finer fissure runs vertically across the branchiostegal 

 flap, in its posterior third. 



The 4th, 5th and 6th abdominal terga are sharply carinated in the middle 

 line, each carina ending in a spine. The 6th abdominal somite is more than 

 twice as long as the 5th. The telson is a good deal shorter than the endopodite 

 of the caudal swimmeret and carries a pair of fixed lateral spines near its apex. 



Byes of moderate size. The antennular flagella are nearly equal in leno-th 

 in both sexes and are longer than their peduncle : in the male they are not in 

 any way modified for prehension as they are in the three preceding species. 



The 2nd joint of the mandibular palp is broad and setose. There is a very 

 strong spine at the end of the ventral border of the basis and ischium of the 1st 

 pair of thoracic legs. 



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

 circular : between the lateral lobes is anteriorly a deep hollow, and posteriorly a 

 tubercle. 



The " andricum " of the 1st pair of abdominal appendages is formed of two 

 equal leaves which are much fimbriated at their free end ; they are not mutually 

 involuted but form a simple canal by their interlocking. 



In the largest female the rostrum and carapace are 28 millim. long, and the 

 extended abdomen is 54 millim. long, measured in the mid-dorsal line. 



Bay of Bengal, off Coromandel coast, 678 fathoms : Gulf of Manar, 180-217 

 fathoms : Andaman Sea, off the North island 185 to 419 fathoms. 



This species though undoubtedly near-related to P. fissunis is distinguished at first sight by 

 the elongate 6th abdominal somite, and by the short dorsally-convex rostrum. 



R e g d. Nos. 2 ^p^ (Types of the species): 918 '^ 9183 : 8 -^ 9 : 2595 ;™\ 



SoEENOCEKA, Lucas. 



This genus differs most markedly from Peneus in the form of the anten- 

 nular flagella, which are foliaceous and channelled along the inner surface, so 

 that when apposed together from opposite sides they form a tube : the inner 

 flagella form the outer walls of the tube and thus ensheathe the outer flagella. 



