I09 



female, almost of the same size, and collected on the coast of Japan ; this specimen has also 

 been referred by Hess to his P. plebejtis. The two females bear such a strong resemblance to 

 one another, even as regards their thelycum, that they were considered also by me to belong 

 to one and the same species when I had the opportunity to study these females in 1 888 

 (vide: Zoolog. Jahrb. II. Abth. f. Syst. 1888, p. 714). In that paper both specimens were 

 referred by me to the typical P. caiialiculatiis Oliv., erroneously because in both females the 

 lateral margins of the telson bear three movable spinules. 



The type specimen from Sydney about which the reader shall find some remarks at 

 p. 1 10, is identical with P. canaliculabis var. australiensis Sp. Bate of the Report on the 

 Challenger Macrura, and the name plebejus has therefore the priority. The other specimen from 

 Japan, however, proved to belong to P. latisulcatus Kish. ; it is 135 mm. long, almost adult, 

 for this species attains the length of 15 cm. It perfectly agrees with Kishinouye's description, 

 the rostrum is '"-dentate and the thelycum has the characteristic form of this species with "the 

 anterior protuberance divided into two thin calcareous horns". 



I was also enabled to examine the specimen from Djeddah, Red Sea, referred by me 

 in 1880 (1. c.) to P. canaliculatus and preserved in the Leyden Museum. It is a young female, 

 long iio mm., that apparently also belongs to P. latisulcatus Kish. The rostrum is 7-dentate 

 and as long as the antennular peduncle. The only difference which I observe between this 

 female and the somewhat larger female from Japan is presented by the two horns in which 

 the anterior protuberance of the thelycum terminates. In the Djeddah specimen these horns are 

 comparatively longer, more slender, tapering, pointed, distinctly curved forward towards the 

 sternum and nearly parallel. In the japanese specimen, however, the two horns are shorter, of 

 a less slender form, less pointed, not parallel, but slightly divergent and not curved forward. 

 As no other differences apparently exist, the different form of these horns may be due to the 

 younger age of this specimen. 



The species described by de Haan (Fauna Jap. Crustacea, p. 190) in my opinion belongs 

 to P. latisulcatus, because the thelycum is described as being "ante medium fissum". His 

 description, however, is inaccurate: in the beginning he says that the third legs are unarmed, but 

 afterwards that they are unispinose. De Haan's species was referred by Dr. Nobili, however, 

 to P. japonicus Sp. Bate (in: Annal. Scienc. Nat. 9^ Sér. T. IV, 190Ó, ^. 10). 



The specimens collected by the "Siboga" are all of a smaller size than the adult female 

 from Japan, but, no doubt, all belong to this species. 



The largest of the 9 specimens from Kawa-bay, a male, is i 1 5 mm. long. The rostrum, 

 as long as the antennular peduncle, is "-dentate, rtve teeth are on the carapace, the i^' is 

 twice as far distant from the 2""^ as the 2"'' from the 3'''^. The groove of the post-rostral carina 

 is much narrower in the middle than the lateral furrows, but, slightly widening backwards, it 

 appears at the posterior end almost equally broad. The spinules on the lateral margins of the 

 telson, three on each, are a little larger than in P. Japonicus Sp. Bate. The rostrum of three 

 other males shows the same rostral formula, but that of the fourth is Y-dentate. The rostrum of 

 one female is broken, in the three others the rostral formulae are ", 7 and v> the last formula 

 being that of a female long 80 mm. In this specimen four teeth are on the carapace, the i^' is 



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