| B4 Mr. G. 8. Brady on Ostracoda 
specimens found in the Scottish glacial clays. The descrip- 
tion of them is therefore left for a ‘‘ Monograph of the British 
Posttertiary Entomostraca,”’ which is now in preparation for 
the Paleontographical Society, by Messrs. Crosskey and 
Robertson, in conjunction with the present writer. I have, 
however, thought it desirable to give here figures drawn from 
the recent Arctic specimens, the joint occurrence of these 
(the only known recent specimens) being of very considerable 
interest In connexion with their distribution in the fossil state. 
Cytheropteron pyramidale, nov. sp. (Plate V. figs. 11-14.) 
Carapace tumid, subpyramidal ; seen from the side, subrhom- 
boidal, highest in the middle, greatest height equal to more 
than half the length ; anterior extremity obliquely rounded, 
posterior narrowed and produced in the middle: superior 
margin very strongly arched, highest in the middle, and 
sloping steeply towards each extremity; inferior convex, 
bending upwards behind. Outline, as seen from above, 
subhexagonal, widest behind the middle, suddenly and 
sharply acuminate in front, strongly mucronate behind ; 
width and height equal. Knd view triangular, sides very 
slightly convex. Shell-surface marked with conspicuous 
fossee, which are arranged in transverse curved rows; ven- 
tral surface sculptured with interrupted longitudinal furrows. 
Length 75 inch. 
Dredged by Messrs. Robertson and Crosskey in 25-30 
fathoms, amongst mud, at Drobak, Christianiafiord. 
This species, though in general appearance approaching 
very closely C. latissimum, differs considerably in the propor- 
tions of the carapace, beimg much more tumid when seen from 
above ; the sculpturing of the surface is also much deeper and 
more distinct, especially on the ventral aspect, and the sides 
are less convex; the contours are also altogether less rounded 
than in its neighbour species. 
Cytherura rudis, nov. sp. (Plate V. figs. 15-17.) 
Carapace, seen laterally, subrhomboidal, nearly equal in height 
throughout ; height equal to more than half the length: an- 
terior extremity obliquely rounded, posterior produced in 
the middle into an obscurely angular beak ; superior margin 
very slightly arched, inferior almost straight: seen from 
above, the outline is ovate, widest in the middle, sharply 
pointed in front, mucronate behind; greatest width equal to 
half the length. End view subpentagonal, widest in the 
middle ; the ventral surface concave, keeled in the middle. 
Surface of the valves covered with rather large angular 
