212 PROFESSOR CHARLES CHILTON ON THE 



This agrees well with the descriptions given by PFEFPER and CHEVREUX, except that 

 the third uropod does not extend much beyond the others. In the upper antennae 

 every second joint of the flagellum is slightly expanded below and bears sensory setse, 

 thus having somewhat the appearance of the flagellum in Paramcera austrina ; in this 

 character the antennae agree exactly with the original description given by PFEFFER. 



I have been able to compare my specimen with those in the Hamburg Museum 

 originally described from South Georgia by Dr PFEFFER, and thus to confirm the 

 identification. 



M. CHEVREUX records the species from Booth Wandel Island. 



Genus BOVALLIA Pfeffer, 1888. 

 Bovallia monoculoides (Has well). 



Atylus monoculoides Haswell, 1880, p. 327, pi. xviii. fig. 4. 

 Bovallia gigantea Pfeffer, 1888, p. 96, pi. i. fig. 5. 



Chcvreux, 1906s, p. 54, figs. 31-33. 

 Stebbing, 1906, p. 357. 



Eusiroides monoculoides Stebbing, 1906, p. 345, and 1910A, p. 595. 

 Chevreux, 1908, p. 475. 



crassi Stebbing, 1906, p. 346, and 1910A, p. 594. 

 esesaris Stebbing, var. Walker, 1904, p. 264, pi. iv. fig. 22 

 Bovallia monoculoides Chilton, 1909A, p. 622. 



Several specimens from shore pools and moderate depths at South Orkneys, 

 Scotia Bay, Station 325. Largest specimen 37 mm. long. 



These specimens agree well with the descriptions of Bovallia gigantea given by 

 PFEFFER and CHEVREUX. They have the last segment of the pereeon and the first two 

 segments of the pleon carinate and produced into an acute dorsal tooth ; the third 

 segment of the pleon bearing a blunt tooth. In smaller specimens these teeth are less 

 marked. They thus agree also with the description originally given by STEBBING for 

 Eusiroides cfesaris, but they differ from it in having the posterior margin of the third 

 segment of the pleon slightly convex and without serrations. The accessory flagellum 

 of the first antenna is present, but is small, and appears to be united with the third 

 joint of the peduncle much in the same way as I have described for the specimens of 

 Atylus megalophthalmus Haswell, which are now considered to be a form of the widely 

 spread Paramcera austrina (Bate). 



Through the kindness of the authorities of the Hamburg Natural History Museum, 

 I have been able to examine co-types of Bovallia gigantea Pfeffer from South Georgia. 

 These are larger than the largest Scotia specimens, and the dorsal teeth are slightly less 

 acute, but there is no difference of any importance. That the dorsal teeth are subject 

 to considerable variation was already known from their varying development in the 

 three species of Eusiroides originally described by STEBBING. Two of these, E, esesaris 

 and E. pompeii, were united by STEBBING in the Das Tierreich Amphipoda, and 



(ROY. 800. EDIN. TRANS., VOL. XLVIII., 494.) 



