338 BRACHIOPODA OF THE 



2. Athyris incerta, Dav. B. S. Sup., PL XXXVIII, fig 5. 



Athyris incerta, Dav. Quart. J. Geol. Soc, vol. xxvi, p. 80, pi. iv, fig. 12, 1869. 



Shell marginally move or less pentagonal, rather wider than long ; dorsal valve 

 moderately convex. Mesial fold broad, flattened, and longitudinally depressed along the 

 middle. Ventral valve slightly more convex or deep than the opposite one, with a broad 

 flattened sinus. Surface smooth. 

 Length 6, breadth 8 lines. 



Of this species only one or two internal casts and an impression of the exterior have 

 been found by Mr. Vicary. It is therefore difficult to arrive at a certain identification. 

 Some indeterminable impressions of an Orthis and of Tentaculites have been found in 

 same pebble. Its age, whether Devonian or Silurian, is uncertain. 



3. Athyris Budleighensis, Dav. B. S. Sup., PL XXXVIII, fig. 6. 



Athyris Budleighensis, Dav. Quart. Journ. G. S., vol. xxvi, p. 80, pi. iv, fig. 14, 



1869. 



Of this fossil the internal cast of the ventral valve has alone been discovered ; it is 

 almost circular, slightly wider than long, with two short slits in the beak, due to dental 

 plates. It measures — length 9, width 9| lines ; and is certainly a Devonian species, for it 

 was found by Mr. Vicary in a sandstone pebble in company with Spirifera Verneuilii and 

 Bhjnchonella inaurita. Similar internal casts have also been found by M. Lebesconte in 

 the Gres Devonien at Gahard in Brittany. I have given the cast in question a provisional 

 name, but it is not perfect enough to warrant a specific identification. 



4, Athyris? erratica, Dav. B. S. Sup., PL XXXVIII, fig. 4. 



Athyris erratica, Dav. Quart. Journ. G. S., vol. xxvi, p. 80, pi. iv, fig. 13, 1869. 



Of this fossil, a single small internal cast has been found by Mr. Vicary. It is 

 therefore not possible to venture upon anything beyond a provisional generic and specific 

 identification. 



In shape the cast is elongate oval, with moderately convex valves. It measures — 

 Length 4, breadth 3, depth 2 lines. 



On the cast of the dorsal valve there exists a long mesial longitudinal indented line, 

 indicating the presence, in the interior of the valve, of a slightly raised narrow ridge, 



