156 



POST-TERTIARY ENTOMOSTRACA. 



fairly referable to C. glohulifera ; but in the absence of further examples it seems best to 

 place it here provisionally. 



Distribution. Recent. — Ireland, Spitzbergen. 



Fossil. — Scotland : Paisley, Govan, Barrie, EUe, Dryleys, Annochie, Errol. Eng- 

 land : Bridlington. Canada : Post-tertiary beds. 



21. Cythere Jeffreysii, Brady. Plate III, figs. 18, 19. 



1868. Cytheee Jeffreysii, Brady. Monog. Rec. Brit. Ostr., p. 412, pi. xxix, figs. 



51—55. 



Carapace, as seen from the sides, oblong, subcuneiform, highest at the anterior third, 

 greatest height equal to more than half the length. Anterior extremity broad, well 

 rounded, fringed below with several (twelve to sixteen) small teeth, and marked with 

 numerous radiating, hair-hke lines ; posterior much narrowed ; superior margin some- 

 what angular over the eye, thence sloping steeply and almost in a straight line 

 backwards ; inferior slightly sinuated in front, then sloping upwards with a slight 

 convexity. Outline, as seen from above, subhexagonal, sides nearly parallel, extremities 

 tapering abruptly, obtusely pointed ; width equal to about half the length. Surface of 

 the shell finely reticulated, the lines of reticulation being made up of moniliform 

 tubercles. 



Length, ^th of an inch. 



C. Jeffreysii has been found recent on the western coasts of Ireland and Scotland, 

 and also off the Channel Islands, but in all these localities is very rare. The surface- 

 marking of the shell is such as is found in the young of species which in the adult stage 

 are strongly spinous ; and a similarly ornamented form, which proved to be the young 

 of C. ec/iinata, Sars, was described by Mr. Brady in the * Zoological Transactions ' under 

 the name of Cythere catenata. Sars's description had not, however, been published at 

 that time, nor had Mr. Brady seen the species in its adult state. The valve of C. 

 Jeffreysii figured in our plate is, probably, a young one; but some of the recent 

 specimens appear to be fully grown, and still exhibit similar characters. We have, 

 therefore, but little hesitation in considering it a distinct species. 



Distribution. Becent. — Great Britain, Ireland. 



Fossil. — Raised beach, Oban. 



