from the Arctic and Scandinavian Seas. 33 



form of the present, which seems to be a peculiarly Arctic 

 species. The points of difference are chiefly these : G. pul- 

 chella has a more boldly arched dorsal margin, is considerably 

 larger, and its greatest width is placed behind the middle ; its 

 hinge-teeth are also much better developed; the terminal 

 claws of all the feet differ remarkably in their conformation 

 from those of G. ruhida, and the urticating setse are also of 

 different type : it is, indeed, chiefly this latter character 

 which induces me to keep the two species separate. From 

 G. villosa it may be distinguished by the colour of the shell, 

 its much more delicate punctation and greater tumidity, as 

 well as by its less-angular lateral outline. The single spe- 

 cimen which obtained G. jpulcliella a place in my monograph 

 of the British Ostracoda was small and probably immature ; 

 and as the fine series of specimens obtained by Mr. Crosskey 

 from Davis's Straits afforded an opportunity for a more com- 

 plete examination, both of the external and internal charac- 

 ters of the species, I have thought it well in this place to 

 redescribe it from the Arctic specimens. It may be noted that 

 the fossil glacial specimens are somewhat intermediate in cha- 

 racter between these and G. rubida. 



Hah. Lat. 67° 17' N., long. 62^ 21' W. Six feet below low- 

 water mark. 



GytJiere Rohertsonij nov. sp. (PL IV. figs. 5, 8-10.) 



Shell of the female compressed, subcuneiform, much higher in 

 front than behind ; greatest height situated at the anterior 

 third, and equal to rather more than half the length : ex- 

 tremities obliquely rounded ; anterior broad, posterior nar- 

 rowed : superior margin straight, sloping steeply from before 

 backwards ; inferior sinuated in the middle, curving upwards 

 behind. Seen from above, compressed, oblong, with nearly 

 parallel sides ; anterior extremity acuminate, posterior sud- 

 denly tapered, obtusely pointed ; width much less than half 

 the length. End view ovate, widest in the middle. Shell 

 of the male much narrower; surface of the shell covered 

 with closely set angular pittings ; colour yellowish. Length 

 sV inch. 

 This very distinct and pretty little species was dredged by 



Mr. D. Robertson, at Drobak, Christianiafiord, in a depth of 



30-35 fathoms. I have much pleasure in dedicating it to its 



discoverer. 



Gytheropteron vespertilio (Reuss). (Plate V. figs. 6, 7.) 



montrosiense, C. B. & B. (Plate V. figs. 1-5.) 



inflatum, C. B. & R. (Plate V. figs. 8-10.) 



Our knowledge of these species is derived chiefly from fossil 

 Ann. & Mag. N. Hist. Ser. 4. Vol.'ii. 3 



