ßO OLAF HOLTEDAHL. M.-N. Kl. 



Raßnesquina, (?) ringerikiensis n. sp. 

 (PI. III, fig. 7 ) 



Mat. pres. Only a single fragmentary ventral valve is present of 

 this beautiful form. 



Description. Shell of medium size, outline semi-circular with 

 cardinal angles only slightly less than 90°. The larger part of the valve 

 is nearly flat, with a slight elevation in the circumbonal region, slightly 

 concave nearer towards the rounded margin, which for a very small width 

 is sharply deflected. At the front this deflection cannot be seen as the 

 specimen here is broken, but it can be studied at the lateral margin. The 

 deflected portion has here a greatest height (width) of only about 3 mm., 

 disappearing totally at the hinge line. 



The radiating striae are of two sizes, the stronger ones placed with 

 relatively small intervals, about i mm. or still less, the number of inferior 

 striæ in each interval being generally 3 — 5. Very fine, crowded, con- 

 centric, raised lines are generally seen. 



What makes even the stronger of the radiating ribs seem very slightly 

 conspicuous, are the very prominent wrinkles that cross them in irregular, 

 undulating, more or less concentrically arranged lines. Generally the 

 wrinkles have a roundedly zigzag appearance. The wrinkles are most 

 conspicuous near the deflected margin, gradually decreasing in size towards 

 the beak. 



Observations. This is a very peculiarly shaped brachiopod, 

 that does not come very near to any other known to me. 



Occurrence: 4b (transition 4 b a— 4 b /:?), Bratterud, Ringerike. 



Rafinesquîna (?) cf. elegans Kiesow. 

 (PI. Ill, fig. 5.) 



1884. Strophoniena elegans Kiesow. Ueber silurische und devonische Geschiebe West- 

 preu&ens. Schriften d. naturf. Gesellschaft in Danzig. N. F. Band 6, p. 251. 

 pi. III, fîgs. 4 — 5. 



1890. Strophoniena elegans Gagel. Die Brach, d. cambr. u. sil. Geschiebe etc , p. 45, 

 pi. III, flg. 20. 



Mat. pres. Only a single fragment of a ventral valve is present. 



Description. Shell of rather small size, outline sub-semi-elliptical. 

 Frontal and lateral margin deflected at about 120°, the length (width) of 

 this marginal rim in median line amounting to about ^/o of the length of 

 the central disc, that is very nearly flat, only at the beak itself a small 

 round elevation is seen. 



