56 POMPECKJ. JURASSIC FAUNA OF CAPE FLORA. [NORW. POL. EXP. 



of the length of the valve, this ridge turns into a flat area, gradually widening 



towards the frontal margin (PI. I. fig. 2). 



For the identification of our pieces with the 

 frequently mentioned species from the Lower 

 Dogger, it was important to examine the for- 

 mation of the interior of the valves (PI. I. figs. 

 3-4). 



Fig. 8. Lingvla Beani, Phill. The inside of each valve shows a broad, 



Outline of PI. I, fig. 2, 

 for correction of fig. 2 a slightly raised, rather Hat rounded mesial ridge, 



Nat. size. extending from the beak to the middle of the 



length of the valve. (On the cast, PI. I. fig. 3, this appears as a shallow groove). 

 In the large valve, this ridge is accompanied on the right and left by a thread- 

 like fillet or ridge, which, under the lens appears to be double, on account 

 of an extremely fine longitudinal furrow. PI. I. fig. 4a and b further shows 

 some of the very superficial muscular impressions of the large valve. The 

 posterior edge of the blended impressions of the anterior adductor and of the 

 external protractor muscles is produced into three unequal lobes. The left 

 and right muscular impressions, divided only by the mesial longitudinal ridge 

 of the valve, are connected in front by the horse-shoe-like impression of the 

 central protractors which surround the anterior extremity of the mesial ridge 

 of the valve. The shape of the muscular impressions of the smaller valve 

 could not be distinctly seen. 



Remarks. The above-mentioned pieces of Lingula Beani Phill. corre- 

 spond perfectly in form and sculpturing with the specimens from the lowest 

 Dogger of Yorkshire and from the Sauzei-/one (Br. Jura y) from the neigh- 

 bourhood of Mietesheim, Gundershofen, Griesbach in Lower Alsace. The 

 more prominent longitudinal convexity of the larger valve (PI. I. fig. 2) may 

 especially often be observed in the specimens from Alsace. 



The form of the muscular impressions in the larger valve unfortunately 

 only visible in a single specimen -- differs somewhat from that we have 

 hitherto been acquainted with in Lingulidse. It differs especially from the 

 drawing which Quenstedt 1 gives as that of the inside of Lingula Beani, but 

 Quenstedt's figure does not represent the inside of a true Lingula Beani Phill. 



F. A. Quenstedt, 1871, 1. c. pi. 60, figs. 83, 84. 



