PROM THE FALKLAND ISLANDS. 337 



Richardson in 1906, as there the inner margin of the large car^^al 

 joint's process is seirate, in place of the well-marked inner tooth 

 of our specimen. 



In the first antennae I found two stout joints, the second 

 longer than the first ; to the second succeeds a minute joint which 

 I suppose to be the third joint of the peduncle. It is followed 

 by a similar joint which should, I think, be considered the fii-st 

 of the slender flagellum. 



In the male the second antennae may attain a great length, 

 fully twice that of the body, the transparent flagellum slightly 

 exceeding that of the peduncle. Pfefter's figure gives this fla- 

 gellum without any divisions, and those which I have marked 

 are very uncertain, notv\ithstanding the high magnification. 

 As shown on the Plate the specimen carrying this long antenna 

 on the right had on the left one very much shorter, and the 

 perseopods on the left are rather shorter than those on the right. 

 Mere size has to be carefully considered before it can be used in 

 classification. 



The curved third joint of the mandibular palp seems naturally 

 to bend away from the cutting-edge rather than towards it. In 

 the rnaxillipeds the broad plate of the second joint has three or 

 four minute hooks on the inner margin and four little teeth on 

 the truncate distal border. 



The first pleopods of the male are described by Hansen as the 

 " median lamella of the abdominal operculum of that sex," and 

 for specific distinction he says " in reality the shape of this 

 lamella, especially its terminal part, aftbrds, perhaps, the sharpest 

 and most reliable character." Unfortunately in small specimens 

 its details are excessively difficult to determine. Even for the 

 larger divisions of the perseon my figures cannot claim exactitude. 



The specimens were obtained by Mr. Vallentin from a hulk 

 at low water. 



AMPHIPODA. 



Family Lysianassid.e. 



Genus Tryphosites Sars. 

 Tryphosites chevreuxi Stebbing. 

 1911. Tryj^hosites chevreuxi Stebbing, Proc. Zoo). Soc, p. 355, pi. 3. 



The original description states that in this species the third 

 pleon segment " has the lower half of the postero- lateral margin 

 convex and cut into a serration of nine little teeth.'' An exam- 

 ination of additional specimens shows the variability of this 

 character, a small example having only three such teeth, and 

 one somewhat larger having four on one side of the pleon and 

 six on the other side. 



In J. Linn. 8oc. vol. xxix. p. 58 ; 1903, Mr. A. 0. Walker 



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