CYTHERE. 165 



Cythere tuherculaia is one of the commonest and most widely distributed of living 

 British Ostracoda, occurring chiefly in depths of 10 — 30 fathoms. Like its near allies, 

 C. concinna, av(/ulata, quadridentata, &c., it exhibits much variation in outhne and in 

 surface-marking, and, as also in those species, the tubercular elevations are much more 

 conspicuous in very young than in old specimens, though the contrary holds good Wiih 

 regard to the pitting or excavation of the shell. 



Distribution. Becent. — Baffin's Bay, Great Britain, Ireland, Norway, Spitzbergen, 

 Bay of Biscay, West Indies, Gulf of St. Lawrence. 



Fossil. — Occurring in nearly all the Post-tertiary beds in the Clyde district ; on the 

 east of Scotland, Gamrie, Annochie, King Edward, Wick, Drip Bridge. England : 

 Bridlington, Hopton Cliff, Branston Een. South Wales : Cardiff New Dock Basin. 

 Ireland : Wood burn, Belfast New Docks. Norway, Post-tertiary beds. 



32. Cytheke Logani, Brady and CrossJcey. Plate XV, figs. 17, 18. 



1871. Ctthere Logani, Bra£?y and CrossAey. Geol. Mag., vol. viii, p. 63, pi. ii, 



figs. 8—9. 



Shell, seen laterally, subquadrate, highest in front, greatest height equal to more than 

 half the length ; anterior extremity broadly and well rounded ; posterior narrower and 

 obliquely rounded ; superior margin straight in its general direction, but much jagged and 

 emarginate throughout, terminating in an obtuse angle behind ; inferior slightly sinuated, 

 curved upwards towards the posterior extremity. Seen from above, the outline is irre- 

 gularly ovate, with obtusely rounded extremities. Surface of the valves marked with 

 large and deep angular fossae, near the middle bearing a rounded tubercle and near 

 the posterior extremity two large tubercular elevations. 

 Length, -^th of an inch. 



It is not without hesitation that we identify the single valve on which the foregoing 

 description is founded with C. Logani ; yet, though the contour of the shell differs in some 

 not unimportant particulars from the types of that species, its general aspect and style of 

 sculpture are so nearly similar that we think it best, for the present at least, to consider it 

 as belonging to the same species. 



Distribution. Fossil. — Scotland : Elie. Canada : Montreal. 



