408 Prof. T. R. Jones on the 



Una and B. uniflexa of Mr. Vine's Collection, and D. colwal- 

 lensis was also referred to it {loc. cit. p. 362). A peculiar 

 form in Mr. Smith's Collection, evidently related to the last, 

 is now to be noticed. 



1. BoUia auricularis, sp. no v. 

 (PI. XIII. figs. 10 a, 10 6, 10 c.) 



Proportions :—L. 22|. H. 12. Th. 9 (and with the 

 ilanges 11^). 



The valves have an irregular oblong outline, straight on 

 the dorsal and sinuous on the ventral edge, if looked at with 

 the flange in sight, but neatly elliptical-convex as seen free of 

 the flange, which projects outward and downward along the 

 greater part of the ventral region, but not so equal and con- 

 tinuous as in Beyrichia Maccoyiana (Ann. & Mag. Nat. Hist, 

 ser. 5, vol. xvii. p. 357, pi. xii. figs. 11 a and lie). The 

 valves are bordered by a thickened marginal rim on the free 

 edges. The centre has a deep bay-like sulcus separating the 

 surface into two unequal subtriangular lobes, united by a 

 narrow isthmus on the ventral region. 



In some aspects this specimen lias a distant resemblance to 

 the outline of the human ear, hence the name. 



One specimen : — Smith Coll. no. 26. llailway-cuttlng, side 

 of Severn, Ironbridge. 



2. BoUia interrupta, sp. nov. (PI. XII. fig. 14.) 

 Proportions :— L. 29. H. 21. 



This form approaches BoUia uniflexa, J. & H. (Ann. & 

 Mag. Nat. Hist. ser. 5, vol. xvii. p. 361, pi. xii. fig. 17), but the 

 posterior lobe is interrupted by a shallow oblique furrow just 

 where it is largest in B. uniflexa. The area, however, of the 

 perfect lobe is approximately indicated by a low swelHng 

 outside and uniting the two contracted lobules that lie within 

 the region of the typical lobe. 



One specimen : — Vine Coll. Bed no. 37. Buildwas Beds. 



IV. Peimitia, Jones & Holl, 1865. 



Most of the Primitice in Messrs. Vine's and Smith's Col- 

 lections have been described or noticed in the Ann. & Mag. 

 Nat. Hist, for May 1886, pp. 409-413, and for March 1887, 

 p. 193. There remains another species, which is related to 

 the simple P. umhilicata type (Ann. & Mag. Nat. Hist. ser. 3, 

 vol. xvi. p. 420, pi. xiii. fig. 2). 



