AMPHIPODA OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 219 



Genus M^ERA Leach, 1813. 



^ I sera mastcrsii (Haswell). 



Megamm-a masttrsii Haswell, 1880A, p. 265, pi. xi. fig. 1. 

 thoimoni Miers, 1884, p. 318, pi. xxxiv. fig. B. 



Msera mustersii Stebbing, 1906, p. 439. 

 ,, Chilton, 1911, p. 594. 



South Africa, entrance to Saldanha Bay, Station 483 ; 25 fathoms. Five 

 specimens, the largest 10 mm. long. 



Although they show some differences, I think these specimens may be referred to 

 this species. On the whole they agree fairly well with HASWELL'S description ; and if 

 the form described as Megamcera thomsoni by MIERS really belongs here, the species is 

 evidently a variable one. My specimens differ from the description given by STEBBING 

 in Das Tierreich in the following points : The third segment of the pleon has the 

 posterior angle produced so as to be acute, but the hind margin is hardly denticu- 

 late ; the eyes are small, almost round ; in the upper antenna the first joint has a stout 

 spinule at its lower distal margin, the accessory flagellum contains seven joints ; the 

 fiagellum of the second antenna is considerably longer than the last joint of the 

 peduncle. In the first gnathopod the carpus and propod are hardly slender, each 

 having the posterior margin convex and agreeing fairly well with HASWELL'S description ; 

 this appendage shows considerable resemblance to that of Elasmopoides chevreuxi 

 Stebbing, but the carpus and propod have the hind margins less strongly convex than 

 in that species. The second gnathopod agrees well with the description. The third, 

 fourth, and fifth perseopoda are fairly stout, the basal joint has the hind margin only 

 finely serrated. The uropoda and the telson agree well with HASWELL'S description. 

 The specimens are colourless (in spirit) and do not show the light yellowish-brown 

 colour mentioned by STEBBING, which was present in the Kermadec Island specimens I 

 examined in 1911. In the rather stout per&eopoda and in some other points they 

 have rather the appearance of an Elasmopus. 



This species is widely distributed in the warmer southern seas. 



Genus PARADEXAMINE Stebbing, 1899. 



Paradexamine pacifica (G. M. Thomson). 



Dexamine pacifica G. M. Thomson, 1879, p. 238, pi. X.B, fig. 4. 

 Paratlexitmina pacifica Steblnng, 1906, p. 518. 

 Chilton, 1909A, p. 632. 

 Paradexamina fissicauda Chevreux, 1906n, p. 88, figs. 51--53. 



South Orkneys, Station 325; 9-10 fathoms. April and May 1903. Four 

 specimens, the largest 17 mm. long. 



(ROY. soc. EDIN. TRANS., VOL. XLVIII., 5<>1.) 



