I05 



Stat. 47. April 8/12. Bay of Bima. Shore. 11 specimens, mostly females. 



Stat. 71. May 10— June 7. Makassar. Depth up to 32 m. Mud. Sand with mud. Coral. 



15 males and 10 females. 

 Stat. 169. August 23/25. Anchorage off Atjatuning, West-coast of New Guinea. Reef, i female. 



Penaetis merguiensis, which in 1892 was identified by me with P. indiais, ought, no 

 doubt, to be considered as a distinct species. When adult specimens of P. merguiensis are 

 compared with the aduh females of P. indicus var. longirostris de Man from Saleyer, described 

 p. 103, their outer appearance is so greatly different, especially as regards the shape of the 

 rostrum that every one will consider them as different species. But even the typical form of 

 P. indictts (Alcock, 1. c. 1906, Fig. 3) differs, like also the variety longirostris^ by the distinctly 

 less slender form of the chelate thoracic legs. Adult males of P. merguiensis are moreover 

 distinguished by the dactylus of the external maxillipeds being only half as long as the propodus. 



The largest specimen from Stat. 47 is a female long 135 mm. The rostrum projects 

 straight forward, is as long as the antennal scales and ^-dentate ; the distance between the 

 foremost tooth of the upper margin and the tip of the rostrum is more than one and a half 

 as long as the distance between this tooth and the penultimate. The rostrum of three other 

 somewhat younger females is --dentate, of another ^ and of a sixth again y- In the other still 

 younger individuals the rostrum is somewhat curved upward and projects a little beyond the 

 antennal scales ; in two of them the rostrum is --dentate, in three other ones ^ , ,; and j. 



The largest male from Makassar is 130 mm. long, the largest female 140 mm. The 

 rostrum of two large males is ^-dentate, of three other ones ^ ; '" three large females the 

 formula is also j, in four other ones y, j, ^ and -. In a young female, long 70 mm., from 

 Makassar the rostrum projects beyond the scales, is slightly curved upward and -.-dentate; the 

 foremost tooth of the upper border is one and a half times farther distant from the tip of 

 the rostrum than from the preceding tooth. In other very young individuals the rostrum bears 

 7 — 8 teeth above, 5 — 6 below. 



In young individuals both of P. indicus and of P. merguiensis the rostrum projects 

 beyond the antennal scales and is more or less conspicuously curved upward : in many cases 

 these young specimens may, however, be distinguished by the teeth of the upper margin, which 

 in P . merguiensis usually occur till near the tip, while in P . itidicus the foremost 

 tooth is situated opposite the terminal joint of the antennular peduncle, so that the distal 

 unarmed part of the upper border appears comparatively longer (vide de Max, 

 I.e. 1892, PI. XXIX, Fig. 53 and Alcock, I.e. 1906, Fig. 3^). 



The female from Stat. 169 is 105 mm. long; the rostrum projects still somewhat beyond 

 the scales, is slightly curved upward and ^-dentate ; the foremost tooth of the upper margin, 

 situated just above the third of the lower, is little farther distant from the tip of the rostrum 

 than from the preceding tooth. 



The male described and figured in the Report on the Challenger Macrura as P. indicus 

 seems to belong to P. merguiensis. 



General distribution: Makassar (de M.\n); Philippine Islands (Spence Bate); Java 

 Sea (de Man); Mergui (de Man); Karachi, Bombay, Palk Strait, Orissa and Ganjam, Hooghly 

 Delta (Alcock). 



105 



SIBOGA-E.^PEDITIK XXXlXa. '4 



