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the Inland Sea of Japan and that was described by me in 1907 under the name of Penaeus 

 (Metapenaeus) acclivis Rathb. (in: Trans. Linn. Soc. 2'"' Ser. Zoology. Vol. IX, Part 11, p. 434, 

 PI- 33' fig- 55)- T'''^ female described in that paper is now lying before me. The thelycum 

 (1. c. fig. 55) has a different form, owing to the large circular outgrowth on the co.xae of the 

 4"' pair of legs, these two processes being separated by a much narrower interspace than in 

 Pen. siridtilans. The legs of the 4"^ and of the 5"^ pairs are somewhat longer and more 

 slender in Pen. stridn/ans than in Pe7t. accllvi.^: so e.g. the legs of the 5"' pair reach in the 

 adult female from Stat. 320 to the terminal fourth part of the antennal scales, but in the female 

 of Pen. acclivis not beyond the two proximal fifth parts of their length. The ridges of the 

 stridulating organ are shorter and situated closer to one another than those of Pen. stridttlatts. 



Penaeopsis akayebi (Rathb.) differs both from Pcti. stridn/ans and Pen. acclivis at first 

 sight by the more elongate shape of the 6* abdominal somite. The two specimens from 

 the Inland Sea of Japan, which I have described in the quoted paper (1. c. p. 433, PI. 33, 

 fig. 54), are lying before me. 



Pen. velutinus (Dana) is also closely related. In this species, however, the telson is 

 much shorter than the inner uropod, whereas in Pen. stridulans they are of the same 

 length or nearly so; the 2°'^ pair of legs are in the Hawaiian species unarmed at base, and 

 petasma and thelycum have a different form (R.a.thbun, in: U. S. Fish Commission Bull, 

 for 1903, Part III, Wash. 1906, p. 903, PI. XX, Fig. 5). Miss Rathbun is no doubt in the 

 wrong, when referring fig. i of Plate XXXIII of the Report on the Challenger Macrura to 

 Dana's species, as is already proved by the fact that she is inclined to exclude the figures 

 of petasma and thelycum. The species which was figured by Spence Bate, seems to be in 

 reality Pen. stridulans. 



General distribution: Orissa coast, Andamans, Ganjam coast, Vizagapatam coast, 

 Madras coast, Palk Strait, Gulf of Martaban, Hongkong, East Indian Archipelago (Alcock). 



f 26. Penaeopsis distinctus (de Man). 



Metapcncus distinctus J. G. de Man, in: Notes from the Leyden Museum, Vol. XXIX, 1907, p. 132. 



Stat. 37. March 3031. Sailus ketjil, Paternoster-islands. Close to reef. 27 m. and less. Coral 



and coralsand. i female. 

 Stat. 1S4. September 11/12. Anchorage oft' Kampong Kelang, South coast of Manipa-island. 



36 m. Coral, sand. 2 females. 



A species of the Akayebi-gro\i^, without stridulating organ, closely related to Pen. 

 inogiensis (Rjjthb.), but distmguished, like from the other species of this group, by the form 

 of the thelycum. 



The two females from Stat. 184 are of equal size, 60 mm. long and somewhat larger 

 than the female from Stat. 37. Rostrum and carapace closely resemble that oi Pen. inogiensis \ 

 in both specimens the rostrum is 7 + i -toothed, the epigastric tooth situated at the anterior fourth 

 of the carapace, in both the ascending rostrum is straight above and below. It reaches just 

 beyond the middle of 2'«i antennular article. Supraorbital tooth, antennal spine and branchiostegal 

 spine as in that species, which was described by Col. Alcock as Metap. mogiensis, but which 



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