58 



J. E. Hede 



This species bears some resemblance to certain shells of Discina Maeotis 

 Eichw. (cfr Barrande, Sil. syst. Vol. V, pl. 100, II), but this last is of smaller 

 size and has a more regular ornamentation with well marked terrace-lines, and 

 radiating stria*. 



Pholidops elliptica n. sp. 



Pl. I, fig. 8 and 9. 



Shell small, longitudinaly elliptical, moderately convex and with the umbo 

 subcentral. The surface shows only few prominent, concentric lines of growth and 

 between them numerous very fine, irregular strise. 



Length about 2,6 mm., width 1,5 mm. 



Locality a. 



Orthis Holsti n. sp. 



PJ. I, tig. 13. 



Shell small, semicircular; greatest width at the hinge line. Both valves strongly 

 convex. Beak well marked, only little exceeding the hinge line. Surface of each 

 valve marked by about 10 strong, radiating, obtuse-angled ribs. Interspaces of the 

 same width and form as the ribs. At the beak the ribs are crossed by from 4 

 to 5 rather coarse growth-lines. Interior not known. 



Very numerously represented in locality a. 



Modiolopsis linguatus n. sp. 



Pl. I, fig. 28. 



Only the left valve is known; it is convex, obliquely elongate, expanding 

 posteriorly. Hinge line straight; anterior end of shell a little narrowed, rounded; 

 posterior end broad, nearly twice as wide as the anterior end, well rounded. Beak 

 small, situated at the anterior end. From the beak a shallow sulcus runs obli- 

 quely back to the inferior margin, which it slightly sinuates. Surface of shell or- 

 namented with fine concentric growth-lines and striae, some of which are stronger 

 than others. 



Length 13 mm., height 7 mm. 



Locality b. 



Ctenodonta retusa n. sp. 



Pl. II, fig. 6. 



Convex, slightly elongate; length : height = 3 : 2. The greatest height over 

 the beak, which is straight, prominent and situated a little nearer to the anterior 

 than to the posterior end. Ventral margin strongly convex. Before umbo the upper 



