338 DR THOMAS SCOTT ON THE 



Genus Cytherura, G. 0. Sars, 1865. 

 Gytherura ornata, new species. (PL XIV. figs. 19-21.) 



Carapace moderately tumid ; seen from the side, subrhomboidal, highest in front of 

 the middle, greatest height equal to rather more than half the length ; dorsal margin 

 well rounded, sloping more steeply in front than behind ; ventral margin flexuous ; 

 anterior margin broadly rounded, obscurely crenulate ; posterior extremity somewhat 

 produced in the middle to a blunt angular point. Seen from above, the sides are evenly 

 and not very strongly convex, widest in the middle, greatest width equal to half the 

 leno'th ; anterior extremity somewhat acuminate, posterior end forming a short angular 

 projection. Surface of the shell ornamented with minute excavations and lines, as 

 shown in the drawing (fig. 19). Length, '54 mm. 



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

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



Cytherura porrecta, new species. (PI. XIV. figs. 22 and 23.) 



Carapace elongated ; seen from the side, oblong, about equal in height at both ends, 

 greatest height less than half the length ; dorsal and ventral margins sinuous ; anterior 

 end boldly and evenly rounded ; posterior extremity produced in the middle line into 

 a prominent subtriangular and blunt-pointed beak ; a sinuous and moderately con- 

 spicuous longitudinal fold extends backwards along the middle line, then curves round 

 to meet the ventral margin. Seen from above, shell outline sagittate, widest in front 

 of the middle, width rather less than half the length ; sides sinuate, abruptly rounded 

 behind, converging in front ; anterior end acuminate ; posterior extremity produced into 

 a prominent beak. Shell surface covered with numerous small and rounded excavations. 

 Length, '45 mm. 



Habitat. This small form was obtained in the same gatherings from Scotia 

 with those described above; Station 325, 60 43' 42" S., 44 38' 33" W. 



Cytherura sculptilis, new species. (PL XIV. figs. 24 and 25.) 



Shell somewhat like Cytherura similis, Brady & Norman ; seen from the side, 

 broadly ovate, highest just in front of the middle, height equal to more than half the 

 length ; dorsal margin strongly arched, sloping towards the anterior end ; anterior 

 slope flattened ; posterior slope evenly rounded and terminating in the posterior angula- 

 tion ; ventral margin arcuate behind, flexuous in front ; anterior extremity bluntly 

 rounded, the margin obscurely crenulated ; posterior extremity produced and somewhat 

 acuminate below the middle, lower edge sloping backwards in a curved line continuous 

 with the ventral margin. Shell, seen from above, broadly elliptical, widest in the 

 middle, width rather less than half the length ; sides evenly rounded, converging more 

 gradually behind than in front ; both extremities somewhat acuminate. Shell surface 



(ROY. soc. EDIN. TRANS., VOL. XLVIII., 584.) 



