TO INDIAN CAECINOLOGT. It? 



to that genus, as vestrit-tcd hy Prof. S. J. Smith ; most of the species are prohahly 

 referable to Parape7i(en.s, Smith, wliicli is characterized chiefly by the absence of 

 branchiae from the last thoracic segment *. A revision of the Penseida?, based on a 

 large collection both of shnllow-water and deep-watev forms, is mucli needed, for at 

 present the genera are in a state of considerable confusion, and Spence Bate appears to 

 have worked independently of the results previously arrived at by Smith. Too much 

 stress has perhaps been laid on certain features of the branchial arrangement, as, for 

 instance, the number of epipodites, in drawing up generic characters. 



269. Pen^us monodox, Pabr. 



F. monodon (Fabr.), Bate, 'Challeiiiicr ' Macrura, p. 250, pi. xxxiv. fifi'. 1 (1888). 



{ = !'■ Hemisvlcatus, De Haan). 



Bombay, Madras. Ganjam, many specimens [Day) ; very common on the Sout'n 

 Indian coast and the chief edible species {J. B. H.). 



The rostrum is about equal to the antennal peduncles, though sometimes longer, and 

 is continued as a sulcate ridge almost to the hind margin of the carapace ; the tooth- 



ft Q 



formula is .^^, with usually three teeth below. The antennular flagella are about 



equal in length to the peduncle. A short longitudinal ridge occurs on the carapace; 

 below the hepatic spine, and parallel to the free margin. The basal joint of the first 

 legs is bispinose, that of the second legs unispinose. The fourth, fifth, and sixth 

 abdominal segments are carinated. The species reaches a length of about a foot. 

 P. tahitensis, Heller, and 7^ curinaliis, Dana, are perhaps referable to this species. 



Distribution. Prom the Pved Sea and E. Africa to Japan. Australia, and the Pacific 

 (Fijis). 



270. PENiETJS iNuicus, Milne-Edw. 



P. indicm (Milne-Edw.), Bate, ' Challenger' Macrura, p. :li9, [A. x.wiii. Kg. 2 (1888). 



(= /'. merguiensis, De Man). 



Kurachi, Madras, Ganjam, Calcutta, Akyab, many specimens {Bay) ; very common at 

 Madras {J. E. H.). 



The rostrum is styliforrn distally, and varies considerably in lengtJi ; in young 

 examples it is usually considerably longer than the antennular peduncles, whereas in 

 adults it is generally shorter than in the young, and is continued as a prominent crest to 

 about the middle of the cara])ace ; the tooth-formula is ^^, with, as a rule, four to six 

 small teeth below. On the carapace the rostrum forms a faint and obscurely sulcate ridge 

 posteriorly, which, however, does not reach the hind margin. The antennular flagella 



* The genus MeUipcnau,, Wood-Jla.son (Ann. Mag. Nat. Hist. scr. 0, vol. viii. p. •2li, 1891), is separated from 

 Parapeuceus by very slight characters, the mo.st important of which is the presence of a rudimentary anterior 

 arthrobranch on the penultimate, thoracic segment, a character which is absent in one of the species referred by 

 Wood-Mason to the genus. 



()3« 



