ENTOMOSTRACA OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 339 



ornamented with fine but irregular reticulations, and with the interspaces minutely 

 punctate ; there are also small whitish papillae where the lines intersect. Length of 

 the specimen represented by the drawing, '5 mm., but another specimen measured 

 only '53 mm. 



Habitat. Scotia Bay, South Orkneys; collected June 1903; Station 325, 

 60 43' 42" S., 44 38' 33" W. 



Genus Paradoxostoma, Fischer, 1855. 



Paradoxostoma retusum, G. S. Brady. (PI. XIV. fig. 26.) 

 1890, Paradoxostoma retiisum, Brady, Trans. Roy, Soc. Edin., vol. xxxv. p. 513, pi. iv. fig. 20. 



Shell, seen from the side, oblong, narrower in front than behind, highest behind the 

 middle ; height rather less than half the length ; dorsal margin moderately convex, 

 evenly rounded except near the posterior extremity, where it becomes slightly 

 flexuous ; anterior end narrow, evenly rounded ; posterior extremity produced above 

 the middle into a bluntly rounded beak, thence, sloping downwards and forwards in a 

 nearly straight line, it merges into and becomes continuous with the sinuated ventral 

 margin. Seen from above, compressed, widest in the middle, about four times longer 

 than wide ; sides evenly rounded, the front end somewhat obtuse, the posterior extremity 

 acuminate. Shell smooth, semitransparent, with a few faint impressed lines at the 

 posterior end (fig. 26). Length, 78 mm. 



Habitat. Scotia Bay, South Orkneys; collected June 1903; Station 325, 

 60 43' 42" S., 44 38' 33" W. 



The Scotia specimens differ slightly from the form described by Dr BRADY in 

 their larger size, as well as to a small extent in their general outline ; the peculiar con- 

 formation of the posterior extremity is, however, quite characteristic of the species 

 referred to. 



Paradoxostoma antarcticum, new species. (PI. XIV. figs. 27 and 28.) 



Carapace ovate ; seen from the side, highest behind the middle, height scarcely 

 equal to half the length ; dorsal margin boldly arched, forming a continuous even 

 curve backwards to the blunt angulation of the posterior extremity, but with a longer 

 slope to the front than to the rear ; anterior end narrow and rounded ; posterior 

 obliquely truncated, slightly produced above, thence sloping downwards and forwards 

 to meet the ventral margin, which is slightly convex. Shell, seen from above, com- 

 pressed, fusiform, widest behind the middle, fully three times longer than broad ; 

 extremities equal and acuminate. Surface of shell smooth, with small, round, indistinct 

 markings scattered over it. Length, - 8 mm. 



Habitat. Scotia Bay, South Orkneys ; collected in June 1903 ; Station 325, 

 60 43' 42" S., 44 38' 33" W. 



(ROY. soc. EDIN. TRANS., VOL. XLVIII., 585.) 



