I02 



exopod, somewhat smaller than those of the preceding legs. It seems to me probable that the 

 seas of India and of the East Indian Archipelago are inhabited only by two or three species 

 of Penaeus^ in which the rostrum is ^--dentate, in which the post-rostral carina is more or less 

 distinctly sulcate and much longer than the lateral grooves and the carapace of which bears 

 a subhepatic crest. These species are i° P. semisiilcatus de Haan, 2" the present species and 

 3" the species described by Alcock (1. c. igo6, p. 8) as P. vionodon, at least when this form 

 should prove to be indeed different from P. semisulcatics de Haan. It is therefore that I don't 

 describe the present species as P. fiionodon, but, as for me, it may afterwards be rebaptized with 

 this name, as soon as the identity of Alcock's t?ioiiodon with P. scuiisiilcatits will be demonstrated. 



P. carijiatiis Dana is a species also of a large size, that attains the length of at least a 

 foot and that occurs at Singapore. The carapace and the rostrum, as figured by Dana, fully 

 resemble the present species and the lateral rostral gropves do not reach backward to the 

 I*' tooth of the rostrum, a character by which P. carinatus Dana is distinguished both from 

 P . semisulcatits de Haan and trom Alcock's P . monodon ; in the present species the rostral 

 grooves extend just as far backward as in Dana's figure. According to this author the flagella 

 of the inner antennae should not be longer than the two preceding joints; the Rev. Stebbing, 

 however, remarks with regard to this description: "as Dana omits these antennae altogether 

 from his figure of the carapace, we cannot be very sure that he knew much about them". 

 (South African Crust. Part III, 1905, p. 75). 



For all these reasons I prefer to describe the present species as P. carinahis Dana, 

 instead of creating a new name again. The principal characters of this species have been 

 already indicated by Alcock. Three of the four females from Makassar are 23 — 24 cm. long. 

 In two females the rostrum is --dentate, in both the 2""^ lower tooth is situated just below the 

 interspace between the 7''^ and the 8"^ tooth of the upper border and in both the 3"' tooth 

 of the lower margin stands in advance of the foremost upper tooth ; in the third female, 

 long 23,5 cm., the formula is t, the i^' lower tooth is implanted opposite the interspace between 

 the 6"' and the 7'"^ tooth of the upper margin and the two following teeth of the lower margin 

 are in advance of the foremost upper tooth. The post-rostral carina of this female is distinctly 

 grooved ; in one of the two preceding females the groove is only developed on its posterior 

 half and in the third the carina shows here only a few impressed pits. The fourth female is 

 190 mm. long. The rostrum bears 7 teeth above, the lower margin only two, the posterior 

 of which is situated just behind the foremost tooth of the upper border, the anterior just in 

 advance of it; the 3''<^ tooth of the lower margin is perhaps broken off and in regeneration, for 

 one observes here a low rounded prominence. The post-rostral carina bears a well developed 

 though shallow groove. 



The antennular flagella are subequal; the upper (outer) flagellum is, in the four females, 

 distinctly longer than the peduncle, i. e. the distance between its tip and the anterior border 

 of the carapace; in the much younger male from Stat. 323 they are, however, shorter than 

 the peduncle, that measures 20 mm., for they are here 17 or 18 mm. long, a difference caused 

 by the younger age of this specimen. The rostrum is '-dentate, two teeth of the lower border 

 are in advance of the foremost upper tooth ; post-rostral groove shallow. 



