121 / 



General distribution: The typical species is known from the East Atlantic (A. 

 Milne-Edwards), from the coasts of Ireland (Stanley Kemp), from the Bay of Biscay (Caullery), 

 from the Spanish coast (VVolfenden) and from the Mediterranean (Adensamer, Ri(;(;io, Senna). 

 The variety scmilaevis Bate was obtained by the "Challenger" between the Philippine Islands 

 and Borneo, off Sydney Harbour, Australia, off the Kermadec Islands and off Matuka, Fiji 

 Islands (Bate and McCulloch). It occurs also at Lion's Head, South Africa (Steuuing), probably 

 also in Sagami Bay, Japan (Balss) and at the Hawaiian Islands (Rathbux). Whether the species, 

 observed by Ai.cock in the Andaman Sea, in the Bay of Bengal and in the Arabian Sea, 

 belongs also to the variety, appears doubtful, because, according to the measurements mentioned 

 by this author, the rostrum should be as long as in the typical species. 



2. Plesionika lon^ipes (A. M.-Edw.) var. indica de Man. PI. X and XI, Fig. 25 — 25,^. 



Pandalits longipes A. Mihie-Edwards, in: Annal. Scicnc. Nat., Zool., (6) XI, 1881, Art. N" 4, 

 p. 15 and in: Recueil de Figures de Crustaces nouveaux 011 peu connus, Avril 1883, PI. 20. 



Plesionika longipes (A. M.-Edw.) var. indica J. G. de Man, in: Zoolog. Mededeelingen, uit- 

 gegeven vanwege 's Rijks Museum van Natuurlijke Ilistorie te Leiden. Deel III, Afl. 4, 

 Dec. 1917, p. 279. 



Stat. 254. Dec. 10. 5°4o'S., 132° 26' E. Near the Kei-i.slands. 310 m. Bottom fine, grey mud. 

 I male and 8 ova-bearing females. 



Plesionika longipes (A. M.-Edw.), which was obtained by the expedition of the "Blake" 

 off the island of Barbados, WestTndies, at a depth of 200 fathoms, is only known by the 

 brief description of 1881 and by the figures published by A. Milxe-Edwards in the quoted 

 "Recueil": this species has never been found again since its discovery by the "Blake". It is 

 therefore very interesting that Pies, longipes has been trawled by the Siboga expedition near 

 the Kei-islands, so that this fact does remind us of Pics, niartia (A. M.-Pklw.) and other West- 

 indian forms which show the same geographical distribution. 



In the specimens, collected by the "Siboga", the number of rostral teeth both on the 

 upper and the lower margin is, however, smaller than in the West-indian typical species, the 

 rostrum is a little shorter, less upturned and the i*' tooth of the upper margin stands a little 

 more forward : it is therefore that they are here described as a new variety indica. 



This species is a true Plesionika, the external maxillipeds namely are furnished with an 

 exopodite, the epipodites are wanting on the last leg only, the posterior lobe of the scaphognathite 

 is broadly rounded and the rostrum is armed dorsally onl\- with fixed teeth. 



The male is 157 mm. long, the females 164 — 190 mm. from tip of rostrum to end of 

 telson : this variety has thus the same size as the typical species and both belong to the largest 

 representatives of the genus. The Table of Measurements shows that the length of the carapace 

 of full-grown specimens varies from 33 to 39 mm.; the carapace appears a little more than 

 one and a half as long as high, the proportion being like 5:3. In some specimens the rostrum 

 is almost one and a half as long as the carapace, in one (X" 5) even slightly more, while in 

 other ones the difterence of length is much smaller. The postrostral carina rises rather suddenly 

 just in the middle of the carapace as a well-defined, though obtuse crest, which in its posterior 



SIBOGA-EXPEDITIE XXXiXrt'. '6 



