84 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53 



The exterior cast shows that the surface was marked by small con- 

 centric ridges and lines of growth with a few low, obscure, rounded 

 radiating ridges and fine granulations or tubercles on the ver}- 

 minute, irregular, more or less inosculating concentric ridges, or the 

 same type of surface as that of Acrothele coriacea Linnarsson [1876, 

 p. 21]. If these shells were found at the same horizon in Sweden as 

 A. coriacea, I think they would be referred to that species, except 

 that the apex of the ventral valve of the French species is much 

 nearer the posterior margin ; more perfect specimens would prob- 

 ably show other differences. 



This species appears to differ from Acrothele qiiadrilincata Pom- 

 peckj [1896, p. 511] and A. hohemica (Barrande) [1879, pi. 102, 

 figs. VII : 1-3] by the more anterior position of the apex of the ven- 

 tral valve. 



In response to a request for permission to study the Cambrian 

 brachiopods that he had collected from Montagne Noire, M. Miquel 

 very courteously sent me a number, and among them I found this 

 species, and, with his permission, have described it. 



It gives me pleasure to give the specific name in recognition of 

 the discovery by Prof. J. Bergeron of the Middle Cambrian fauna 

 of Herault, and of his fine work on the fauna. 



Formation and Locality, — Middle Cambrian: Shales, in Mon- 

 tagne Noire, Coulouma, Department of Herault, France. 



ACROTHELE BORGHOLMENSIS, new species 



Plate 8, Figure 12 



General form subcircular to broad oval. A^entral valve subcon- 

 ical, with the apex a short distance back of the center. A clearly 

 defined false area extends from the apex to the margin ; it is defined 

 by a slight depression and a low ridge at the outer edges ; two or 

 three longitudinal lines extend to the margin and the concentric 

 lines of growth of the shell cross it without interruption. An elon- 

 gate, small foraminal aperture occurs just back of and beneath the 

 apex. 



The outer surface of the shell is of a dull, dark color and marked 

 by slightly undulating, clearly defined, concentric striae ; the inner 

 layers are marked by fine radiating and concentric lines. The shell is 

 built up of thin lamellae arranged in concentric layers that are slightly 

 oblique to the surface layer. Shell substance corneous. Nothing 

 is known of the interior of the valves except the sharp median ridge 

 of the dorsal valve. 



The largest specimen has a diameter of 4 mm. ; the average size 

 is about 3 mm. 



