F. R. Coioper Reed — Fossils from Haverfordtvest. 497 



angle, increasing in heiglit to middle, then decreasing behind and 

 merging into general convexity of valve. Surface of shell orna- 

 mented with numerous fine, regular, equidistant, straight, radiating, 

 raised lines running from beak to inferior margin on anterior two- 

 thirds of shell, but faint or absent on posterior portion ; crossed by 

 rather irregular, somewhat undulating, not always equidistant, fine 

 concentric fimbriations which become much more numerous and 

 regular on posterior third of shell where the radii are absent. 



Dimensions. 



Length 9-0 mm. 



Height 7"0mm. 



Thickness (one valve) 3*5mm. 



Horizon and Locality. — Eedhill Beds : 80 yards north of 

 Prendergast Place, Haverfordwest. 



Remarks. — The true generic position of this pretty little shell is 

 somewhat doubtful, for though we have the internal cast of the 

 shell and external imprints of the surface, the cardinal portion is not 

 well preserved, and the region near the beaks is somewhat abraded. 

 No trace of teeth is visible, but the ligament seems to be external 

 behind the beaks. I am inclined to associate it with Cyrtodonta, 

 some species of which bear much resemblance in external shape, 

 though the ornamentation in our specimens is peculiar. ^ 



Whitella (?) iNUTiLis, sp. nov. (PI. XXIV, Figs. 7, 7a.) 



Description. — Shell small, oblique, very elongate-ovate, some- 

 what wedge-shaped, narrowing posteriorly ; strongly ventricose and 

 inflated. Hinge-line short, straight behind beaks, and less than 

 one-third the oblique length of the shell, meeting posterior margin 

 at angle of about 135°, with elongate narrow escutcheon grooved on 

 each side for reception of ligament. Posterior end of shell much 

 produced, very obliquely truncated, margin nearly straight, with 

 inferior angle acutely rounded ; inferior margin slightly arcuate, 

 inclined to posterior margin at about 30°-40° ; anterior end of shell 

 very short, rounded. Beaks rather prominent, small, acute, directed 

 forward, rising above hinge-line, incurved, situated at about one- 

 third the length of hinge-line. Strongly elevated, subangular 

 umbonal ridge, slightly arched upwards, running from beak to 

 posterior basal angle, nearer upper than lower margin of shell, 

 giving valves an inflated appearance ; convexity of ridge increasing 

 from beak to middle of valve and then decreasing gradually to 

 extremity. Surface of shell marked with rather strong concentric 

 striae and wrinkles, and by a few faint, gently curved, radiating striae, 

 especially distinct on the region anterior to the umbonal ridge. 



Dimensions. 



Length 15"0mm. 



Height ... ... ... ... ... ... 8"0mm. 



Thickness 6'5mm. 



Horizon and Locality. — Slade Beds : roadside near St. Martin's 

 Cemetery, Haverfordwest. 



DECADE V. — VOL. 11. — NO. XI. 32 



