178 



POST-TERTIARY ENTOMOSTRACA. 



from C.jJapillosa by its dull, unpolished surface, distinct punctation, and less conspicuous 

 papillae, as well as by the anterior elevation of the dorsal margin and the less exserted 

 infero-posteal angle ; it is also a considerably smaller species. The young forms of the 

 two sexes are represented at figs. 6 and 7. C. puncHUata approaches closely Bosquet's 

 ^' Bairdia" {Cythendea) jjunctatella, and B. Hebertiana, as also {fide Bosquet) to C. 

 Muelleri, Miinster; but it is not strictly referable to any of these forms. M. Bosquet 

 himself considers it a distinct species. 



Distribution. Becent. — Baffin's Bay, Gulf of St. Lawrence, Spitzbergen, Norway, 

 Britain. 



Fossil. — Occurring in nearly all the Scottish beds. Ireland : Woodburn and Portriish. 

 England : Bridlington. 



Z. Cytheridea TOROSA (/o;|^es). Plate XV, figs. 11, 12. Fr/r. teres, Plate VII, figs. 1, 2. 



1850. Candona TOROSA, Jbwes. Ann. Mag. Nat. Hist., ser. ii, vol. vi, p. 27, pi. iii, 



fig. 6. 



1856. Cypkideis — , Jonei. Monog. Tertiary Entom., p. 21, pi. ii, figs. 1 a — 1 i, 



and Woodcut, fig. 2, p. 16. 

 1870. Cytheridea torosa, Brady and Robertson. Ann. Mag. N. H., ser. iv, 



vol. vi, p. 21, pi. viii, 

 figs. 6, 7. 



Carapace of the female, as seen from the side, oblong, subelliptical, greatest height in 

 the middle, and equal to rather more than half the length. Extremities rounded, the 

 posterior narrower and rather oblique. Dorsal margin gently and evenly arched, ventral 

 straight or very slightly sinuated in front ; at the infero-posteal angle there is often a 

 short thick spine. Outline, as seen from above, oblong ovate, having on each lateral 

 margin several (usually three) equidistant nodular projections with intervening sulci. 

 The right valve is smaller than the left and slopes away much more steeply behind. The 

 shell of the male is as usual much narrower, longer, and more angular. Shell very thick 

 and strong, marked Avith closely set, rounded pittings, and bearing on each valve several 

 (usually four) large, rounded, prominent tubercles. Colour yellowish or greenish- 

 brown. 



Length, -^-gth of an inch. 



Var. teres. Plate VII, figs. 1, 2. 



^ 1864. Cyprideis torosa, Bradij. Trans. Tyneside Nat. Field Club, vol. vi, p. 108, 



pi. iii, figs. 11—23, and Ann. Mag. N. H., 

 ser. iii, vol. xiii, p. 62, pi. iv, figs. 11 — 23. 

 1865. Cyprideis torosa, G. O. Sars. Overs. Norg. mar. Ostrac, p. 51. 



