532 A Revision of the ^^ Genus'''' Peneus. 



sharply carinated. The fifth abdominal somite is about two 

 thirds the lenojth of the sixth, the sixth is about as long as 

 the telson. The tclson, which is dorsally grooved, is much 

 shorter than the inner caudal swimmeret, ends rather 

 abruptly, and has on either side a very obscure subtermiual 

 marginal spinelet. 



Theantennular flagellaof the male are about three fourths, 

 those of the female about two thirds the length of their 

 peduncle; the lower flagellum is much the coarser. The 

 tliird maxillipeds are coarse, except the dactylus, and reach 

 into the anterior third of the antennal scale. The last pair 

 of thoracic legs reach at least a dactylus-length beyond the 

 tip of the antennal scale. A basal spine is present on the 

 first two pairs of chelipeds. All the thoracic legs have 

 petaloid exopodites. 



The andricum is anchor-shaped. 



The thelycum consists of a trans ver-e bar between the 

 fifth pair of legs and a concave semicircular plate between 

 the fourth. 



The female reaches a length of 3f inches. The colours in 

 life are pink, the abdominal carinse and thoracic appendages 

 being milk-white. 



The species has been taken in the Persian Gulf, off the 

 Vizagapatam and Ganjara coasts in depths of 20-35 fathoms, 

 and off the Andamans in 60 fathoms. 



It diffrrs from T. curvh'ostris, Stimpson {=T. anchoralis, 

 Spence Bate), of which we have both 'Challenger^ specimens 

 from Japan and other specimens from Hongkong, in the 

 following particulars : — 



The rostrum is quite straight and has more teeth, and the 

 postrostral carina is much fainter. 



The antero-inferior angles of the carapace are sharper and 

 the anterior part of the cervical groove is much less distinct. 



The antennules are shorter both in their peduncle and in 

 their flagella, and the fifth pair of legs are longer. 



Though the andricum is similar, the thelycum is a good 

 deal different, specimens of the same size being compared. 



