158 



POST-TERTIARY ENTOMOSTRACA. 



above, obloug-ovate, widest in the middle, width less than the height. Shell of the male 

 narrower, more compressed, about twice as long as high ; upper margin nearly straight 

 and sloping from before backwards, inferior also nearly straight, the post-median angular 

 prominence more conspicuous than in the female. Hinge-teeth strongly developed; 

 surface of the valves sculptured with deep and large fossae, which often assume towards 

 the margins a somewhat radiated arrangement (figs. 7 and 12) ; at other times, probably 

 in old specimens, they become indistinct (fig. 8) and in the centre obsolete. 

 Length, 4^th of an inch. 



Cythere villosa is a common recent species, occurring plentifully on the shores of 

 Britain (except on the east coast, where it is rare) and Norway in the littoral and 

 laminarian zones, but not often extending into great depths ; it is also one of the 

 commonest of the Glacial Ostracoda. 



Distribution. Mecent. — Great Britain, Ireland, Norway, Bay of Biscay, Davis's 

 Straits, Gulf of St. Lawrence, 



Fossil. — Common in nearly all the Scottish Post-tertiary beds. England : Hopton • 

 Cliff, Whittlesea. Ireland : Belfast New Docks, Portrush. Norway. 



24. Cythere laticarina, Brady. Plate IX, figs. 23 — 26. 



1868. Cytheke laticarina, Brady. Monog. Rec. Brit. Ostrac, p. 412, pi. xxxi, 



figs. 1 — 4. 



Carapace of the female (?), as seen from the side, subquadrate, highest in front, greatest 

 height equal to more than half the length. Anterior extremity broadly rounded, fringed 

 below with numerous (about sixteen) very fine teeth; posterior rounded, narrow, 

 emarginate above the middle ; superior margin prominently angular over the anterior 

 hinge, from which it slopes backwards in a slightly jagged line ; inferior sinuated in the 

 middle. Outline, as seen from above, subhexagonal, with parallel sides and very blunt, 

 equally tapered extremities ; greatest width in the middle and equal to about half the 

 length. The surface of the shell is uniformly sculptured with rather large subquadrate 

 pittings, and the eye-tubercles are large and exceedingly prominent ; the margins of the 

 valves very broad and thick, forming a wide encircling fillet or keel. 

 Length, -^rd of an inch. 



This is very distinct from all other species, except perhaps C. maryinata, Norman, of 

 which one specimen only is extant, and which must be looked upon as a somewhat 

 doubtful form. Though bearing some resemblance to C. tuber culata, C. laticarina is easily 

 distinguished from that species by the different proportions, and even contour of the 

 carapace, as well as by its much thickened margins. A certain soft, woolly appearance of 



