.Skånes Oolonusskiffer 



59 



margin is dipping forwards, behind umbo it is abruptly bent down. No ornamen- 

 tation is to be seen. 



Closely similar to Ctenodonta securiformis Grönw. but distinguished from this 

 by its less elongate form and more obtuse submedian umbo. 



Locality a. 



Lunulicardium caudagalli n. sp. 



Pl. II, fig. 4 a and b. 



Equivalve, convex, with terminal beak, strongly bent forward. Anterior and 

 basal margins semicircularly rounded. The posterior margin, slightly convex, forms 

 with the basal one a slightly obtuse angle. The surface, with except of the smooth 

 beak, with about 40 radiating ribs, sharp, thread-like and rarely splitting. While the 

 hindmost ribs are parallel with the posterior margin, the following ones bend more 

 forwards, so that the foremost are making right angle to the hindmost ones. The 

 ribs follow each others like the feathers in a cock's-tail. The interspaces between 

 the ribs are of the same width and form as these. Also very fine concentric 

 growth-lines are to be seen. 



Locality a. 



Antipleura? cucullaeiformis n. sp. 



Pl. II, fig. 19. 



Convex, rounded triangular, with the posterior end long, obliquely truncate. 

 Anterior end rounded, in an even curve passing over into the slightly convex lower 

 margin. Posterior margin nearly straight. The large and prominent beak curves 

 somewhat backwards. A carina, a little backwards concave, runs from the beak to 

 the posterior angle, thus bordering the little, steeply sloping posterior area. The 

 anterior side of the beak is bordered by a furrow which, gently marked, runs nearly 

 straight down to the lower margin. 



The surface of the shells exhibits fine, somewhat irregular, thread-like, radia- 

 ting ribs, and fine growth-lines which in the umbonal part are accompanied by 

 shallow but distinctly marked concentric folds. 



Locality a. 



Maminka? suecica n. sp. 



Pl. II, fig. 20. 



Elongate, subovate. Very convex. The pointed beak is slightly bent down- 

 wards and backwards, and situated a little before the middle of the hinge 

 line. The rounded anterior margin without break passing over into the gently 

 convex lower margin. The posterior margin short, obliquely truncate, seems to 

 form nearly right angle with the lower margin. From the beak a carina, backward 



