BUDLEIGH-SALTERTON PEBBLE-BED. 343 



deep sinus in the ventral valve; beak small and incurved. Surface of valves covered 

 with a variable number of ribs, from sixteen to twenty-eight in each valve, of which 

 from four to seven occupy the fold, two to five or six the sinus. In the interior of the 

 dorsal valve there exists a short mesial septum, on each side of which are situated the 

 muscular scars (fig. 23). 



Length 8, depth 8^ lines. 

 Whether this Rhynchonella be referable or not to Schnur's species, it is one of the 

 commonest in the Devonian pebbles of Budleigh-Salterton, and occurs in company with 

 Spirifera Verneuilii and Rh. inaurita. This identification must, however, be considered 

 as provisional. Similar internal casts are found in the Yellow Sandstone, " Gres 

 Devonien," at Gahard, in Brittany. 



13. Rhynchonella Vicaryi, Dav. B. S. Sup., PI. XXXVIII, figs. 30, 31. 



Rhynchonella Vicaryi, Dav. Quart. Journ. Geol. Soc, vol. xxvi, pi. v, figs. 7, 8, 1869. 



Internal casts only have been found. Shell small, somewhat trigonal and com- 

 pressed, longer than wide, broadest anteriorly, tapering at the beaks. Valves moderately 

 convex ; each valve ornamented with ten or eleven ribs, of which four to five compose the 

 fold, three or four the sinus, 



Length 5|, width 5 lines. 



Of this small species I have seen several internal casts, but not sufficient to enable 

 me to give a complete or satisfactory description of the shell. Mr. Vicary found it in 

 the same pebble along with Spirifera Verneuilii. 



14. Rhynchonella Valpyana, Dav. B. S. Sup., PI. XXXVIII, figs. 33, 34. 



Rhynchonella Valpyana, Dav. Quart. Journ. Geol. Soc, vol. xxvi, figs. 26, 27, 1869. 



Shell small, longitudinally oval or ovate. Valves moderately convex. Surface 

 ornamented with about thirteen simple ribs, of which the three largest form the mesial 

 fold. 



Length 5, width 4, depth 3 lines. 



Two or three internal casts and an external impression have been found by Mr. 

 Vicary. It is a Devonian fossil. 



