366 Messrs. Brady and Robertson on Dredging 



middle, and equal to fully half the length ; extremities 

 rounded : superior margin boldly arched, sloping more 

 abruptly in front than behind ; inferior sinuated in the mid- 

 dle. Seen from above, compressed ovate, widest in the 

 middle ; extremities equally pointed ; width much less than 

 half the length ; end view subrhomboidal, widest in the 

 middle. Shell thin and fragile, semitransparent, smooth, 

 thickly covered with very short delicate hairs. Length 

 tt inch. 

 Ilab. In sand from Scarpa Bay, Orkney (D. O. Drewett, Esq.) ; 

 and in the river Liffey at North Wall, Dublin. 



The locality (Shetland) given in the l Monograph ' was in- 

 serted by mistake for Scarpa Bay. The specific name fulva 

 does not well apply to the specimens here described, they 

 being almost colourless ; but the discrepancy is scarcely im- 

 portant enough to warrant a change of name*. 



Fam. Cytheridae. 



Genus Cytheee, Muller. 



Cy there porcellanea, Brady. PI. XIX. figs. 1-4. 



Ct/there porcettanea, Brady, Ann. & Mag. Nat. Hist. ser. 4. vol. iii. p. 47, 

 pi. 7. figs. 1-4. 



Carapace of the female, as seen from the side, flexuous, reni- 

 form, highest in the middle, greatest height equal to rather 

 less than half the length ; anterior extremity evenly, poste- 

 rior obliquely rounded : superior margin evenly arched, in- 

 ferior deeply sinuated in the middle ; postero-superior angle 

 well marked. Seen from above, ovate, widest in the mid- 

 dle, pointed in front ; width less than the height. Shell- 

 surface smooth and polished, marked often behind the mid- 

 dle with a few scattered indistinct puncta. Colour whitish. 

 Length -^ inch. Carapace of the male in shape much like 

 that of the following species, except that the outline, when 

 seen from above, is regularly ovate. 



Ilab. Westport Bay, 4 fathoms ; and on the muddy shore of 

 Budle Bay, Northumberland, near low-water mark (G.S.B.); 

 and Dungeness Bay, and River Ouse at Lynn (Mr. E. C. 

 Davison's dredgings). 



The Dutch specimens from which this species was originally 

 described appear to be either young or stunted individuals ; 

 and the figures which accompanied the description do not give 



* Since this was in the printer's hands, I have seen examples of B. fulva 

 in dredgings from the Dutch localities mentioned above ; so that this 

 species would seem to come into the category of fiuvio-niarine species, to 

 which Cypridopsis obesa also belongs. — G. S. B. 



