496 F. R. Coicper Reed — Fossils from Haverfordicest. 



considered identical with it. McCoy's so-called Area scitula ^ bears 

 a considerable external resemblance to our Redhill form, but no 

 information as to the internal characters of this Irish shell has been 

 published. 



Arca (Pal^akca) Turnbulli, sp, nov. (PI. XXIV, Fig. 14.) 



Description. — Shell oblong, more than twice as long as high; 

 convex, most so about middle ; hinge-line straight, about three- 

 fourths the length of shell ; beaks broad, obtuse, directed forward, 

 rising above hinge-line, incurved, situated at about one-fourth the 

 length of hinge-line from front end, and at about one-third to two- 

 fifths the length of shell ; anterior end of shell obliquely truncate 

 above, acutely rounded at inferior angle ; inferior margin slightly 

 arcuate ; posterior end obtuse, abruptly truncate, not produced, 

 meeting hinge-line at about 60°-70°. Teeth transverse, inclined 

 away from beak, about 8-10 visible behind beak. Surface of valves 

 moderately convex with umbonal ridge running obliquely back ta 

 posterior end at angle of about 20° to hinge-line ; cardinal slope 

 behind and above umbonal ridge compressed, flattened ; anterior end 

 in front of beaks somewhat depressed above, but convex below. 

 Surface of shell marked with fine concentric stride and weak growth- 

 wrinkles. 



Dimensions. 



Length 20-.5mm. 



Height 9-omm. 



Locality and Horizon. — Slade Beds: roadside 150 yards west 

 of St. Martin's Cemetery, Haverfordwest. 



Remarks. — This species resembles A. edmondiformis} but the 

 shell is relatively longer, the beaks are more central, and the 

 truncation of the ends is different. Portlock's Arca cylindrical 

 is more elongated and the beaks more anterior ; and in his 

 A. suhtrimcata^ the shell is shorter and broader, and the beaks 

 are more centrally situated. 

 CyRTODONTA (?) CANCELLATA, sp. nov. (PL XXIV, Figs. 11, 11a.) 



Description. — Shell quadrato-ovate, slightly oblique, truncated 

 abruptly in front, broadly rounded behind, about 1^ times as long 

 as high, widening a little posteriorly ; surface moderately convex, 

 most so about middle of valves. Beaks anterior, low, small, scarcely 

 rising above hinge-line, directed forwards. Anterior margin nearly 

 straight, abrupt, meeting inferior and superior margins at nearly 

 right angles. Inferior margin slightly arcuate. Posterior end 

 obtuse, broadly rounded below, obliquely truncate above. Superior 

 cardinal margin straight, about three-fourths the length of shell. 

 Hinge-line bent at nearly a right angle at beaks. Broad, rounded, 

 ill-defined umbonal ridge running obliquely from beak to posterior 



^ McCoy: Sjiiops. Silur. Foss. Irel., p. 20, pi. ii, fig. 6. 



2 McCoy: Synops. Brit. Pal. Foss. "VVoodw. Mus., p. 283, pi. Ik, figs. 2, 3. 



3 Portlock: Geol. Eep. Londond., p. 428, pi. xxxiv, fig. 9. 

 * Ibid., p. 427, pi. xxxiv, fig. 1. 



