253 



4. BAIRDIA JUDDIANA. JoneS. 



i^uart. Joiirn. Geol. Soc, vol. xl., 1884, p. 767, pi. xxxiv., fig. 18. 



One perfect example of this boldly characterized Bairdia 

 occurs in the Blue Fullers-earth Clay at Midford. It is well 

 known to us as occurring in the Lias, and from the Richmond 

 boring. 



5. BAIRDIA TRIGONALIS, JoneS. 



Quart. Journ. Geol Soc, vol. xl., 1884, p. 767, pi. xxxiv., fig. 19, 

 Two valves of this species occur in the Blue Fullers-earth 

 Clay, Midford. 



6. BAIRDIA rULLONICA, Sj?. U. 



PI. v., figs. 4 a, b, c. 



Of the usual subdeltoid outline, evenly convex, smooth, and 

 delicately punctate. We do not, however, know any form yet 

 figured that exactly matches these specimens from the Fullers- 

 earth Oolite. Edge view, lanceolate ; end view, sharp-oval. 



Two examples ; Blue Fullers-earth Clay, Midford. 



7. Three examples of Bairdia, more nearly approaching to 

 B. Hilda (Qvart. Journ Geol. Soc, vol. xl., 1884, p. 771, pi. xxxiv., 

 fig 20) than to others, occur in the Blue Fullers-earth Clay of 

 Midford ; also a single valve of a Bairdia very near to the 

 smaller valve of B. Jurassica (loc. cif., fig. 22.^ 



8. CYTHERE SPH.^RTJLATA, sp. 11. 



PI. i., figs. 6 a, h, c. 



Broadly sub-oblong and convex, with the antero-dorsal border 

 very oblique, and the posterior end well rounded. Surface 

 ornamented with minute tubercles arranged in curved lines, 

 resembling strings of beads, and becoming straighter, but con- 

 fused in the dorsal region. Edge view, long-ovate ; end view, 

 sub-cordate or broadly ovate, with flat base. 



