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teeth of the upper border closely resemble Alcock's figure i (l.c. 1906), hut the lower marL^in 

 bears four teeth of which three are implanted in advance of the foremost tooth of the upper 

 margin, the first being just below that foremost tooth. The first tooth of the upper margin is 

 placed a little more backward than in Alcock's figure, its place more agrees with Fig. i of the 

 Challenger Report. The 4"^ abdominal somite is carinate in the two posterior thirds of the tero-um. 

 The three small, obHque ridges that are situated, as in other species, on the lateral surface of 

 the 6''' somite, the two on the 5"' and the one on the 4''^ are wanting in Alcock's figure. 



The antennular flagella are of equal length, 15 mm. long, considerably shorter than the 

 distance (22 mm.) between the tip of the antennular peduncle and the frontal border of the 

 carapace. The upper (outer) flagellum is widened almost along its proximal half and this 

 dilated part, which is feebly grooved below, is 7 mm. long; though this widened portion seems 

 somewhat to narrow distally when it is looked at from above, it does not regularly and 

 gradually pass into the filiform distal part of the flagellum. In Alcock's figure i both flagella 

 seem to taper regularly to their extremities. The third legs reach just beyond the tips of the 

 antennal scales. 



In the second male long 80 mm. and in the third long 74 mm. the rostrum shows the 

 same characters as in the first, as regards the number and the arrangement of the teeth, except 

 that the lower margin bears 3 teeth instead of 4 ; the rostrum of the youngest specimen extends 

 just beyond the tip of the antennular peduncle and the distance (4,5 mm.) between the tip ot 

 the foremost upper tooth and that of the rostrum is one and a half as long as the distance 

 between the tips of the 5* and of the 7'^ tooth. The antennal flagella of these three specimens 

 have lost their coloration ; in the male, long 105 mm., from Rottilsland, however, the coloured 

 rings are still visible. The rostrum of this specimen resembles that of the largest male from 

 Stat. 213, but there are only 3, instead of 4, teeth on the lower margin. The carapace is 36 mm. 

 long, rostrum included; the first upper tooth is 9 mm. distant from the anterior margin of the 

 carapace and 11,5 mm. from the posterior. 



In all the specimens collected by the "Siboga" the post-rostral carina is distinctly sulcate, 

 the I*' pair of legs are bispinose, the 2"<^ unispinose, the 3''^ are unarmed. 



I may, finally, remark that in this species, different from P. cai'inahis (Dana) de Man, the 

 subhepatic "crest" appears as a narrow, linear groove and hardly may be described as a crest. 



R e m a r k s. The main cause why P. semisulcatus de Haan has been so often confounded 

 with the species described in this Report as P . carinattis Dana, is, in my opinion, the fact 

 that DE Haax's description is perfectly well applicable to both species. 



The specimens from Makassar, referred by me (l.c. 1892, p. 510) to P. semisulcatus, 

 proved, after a new examination, to belong partly to this species, partly viz. the adult specimens, 

 to P. carhiahts Dana. Also the young specimen from the Java Sea, described by me in another 

 paper (l.c. 1898, p. 677) as P. semisulcatus, appeared, after a new examination, to belong 

 indeed to this species. 



With regard to Penaeus caeruleus Stebbing, in: South African Crustacea, Part III, Cape 

 Town 1905, p. 77,- PI. XXI and XXIbis), I may add the following, having been kindly enabled 

 by the Rev. Stebbing to examine one of the type specimens from Nahoon River near East 



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