340 "EVDEAVOrR" SCIENTIFIC RESULTS. 



The smaller male has the carina on the third abdominal 

 somite grooved throughout. Its external maxillipeds are 

 comparatively as long as those of the larger male. If 

 anything, the fringes on the petasma are more distinctly 

 indicated in this specimen than in its fellow, or even 

 the male of novce-guinece above. 



The smallest female of this "palmensis" lot is some- 

 thing else. There is no stridulating organ present. The 

 rostrum has eight teeth above, counting the epigastric, 

 of which all but the latter are in front of the posterior 

 margin of the orbit. The small carina on the second 

 abdominal somite is blunt and imgnooved, as is also 

 the carina on the third somite. The specimen has all the 

 ear-marks of a true P. mogicnsis. The thelycum is very 

 close to, if not identical with, the one figured by de 

 Man 33 as the Penwopsis sp. for which he suggests the 

 name liUnrulus. Though I have not seen any P. mogicnsis 

 identified by Alcock, I am unwilling to concede the 

 identity of de Man's specimen with Alcock's mogienxis 

 to the exclusion of Miss Rathbim's species of that name. 

 Alcock's description tits Miss Rathbun's species, and his 

 figure of the thelycum is nearer the typical species than 

 is the one given by de Man. Between the four pairs 

 of legs, the median teeth, as Alcock calls them, might 

 well be described as platelets. These usually diverge 

 only at their tips, as is shown by Alcock, rarely so 

 pronouncedly as in the case of Miss Rathbim's figured 

 type from Mogi, Japan. 34 The more usual, and possibly 

 less mature type, of a specimen 82 mm. long from Minato, 

 Satsunia, Japan, is shown in tig. 4 of Plate Ixi. The 

 anterior of the two parallel transverse plates lying 

 between the fifth legs are in both figures, Miss Rathbun's 

 and Alcock's, cut into two laminae, each of which may 

 again be cut into two teeth. In the specimens in the 

 collection of the U.S. National Museum, these teeth are 

 more as delineated by Miss Rathbun, and not at all 

 so sharply dentiform as Alcock has them in his figure, 

 which I take to be a variatioual extreme. It is in the 

 case of this very plate that de Man's 35 Penceopsis sp. 

 (or P. Jiila ruins) differs from both the mogiensis of 

 Alcock and Rathbun, inasmuch as it is all in one piece 



:<s "Siboga" Exped., xxxixa. Decapoda, pt. i., Penaeidse, 1911 

 (plai.es 1913), p. 70, pi. vii., figs. 22o-22d. 



"Rathbun, Proc. U.S. Nat. Mus., xxvi., 1903, p. 40, fig. 8. 



35 "Sibogai" Exped., xxxixa Decapoda, pt. i., Penaeidae, 1911 

 (plates, 1913), p. 70, pi. vii., figs. 22a-22d. 



