KONGL. SV. VET. AKADEMIENS HANDL. HANI). 19. N:() 6. 103 



Height 25 inilliiu., width of body whorl 17 inilliin. Height of iiporture 12 iniilim. 

 Width of body whorl in u fragmentary specimen 23 millim. 



A few specimens have been found in the uppermost limestone of Klinteberg, 

 Frojel and Wisby (b. c). 



15. Pleurotomaria tubulosa n. 



PI. IX fig. 7—10. 



Shell turbinated, with ventricose whorls, of which only the body whorl and part 

 of the next are left, in the only specimen, which has been found. The slit band is 

 placed somewhat beneath the median line of the body whorl, relatively narrow, pro- 

 minent and much convex, the crescents much more distantiated than in any one of 

 the other Silurian Pleurotomarias and continue backwards as a narrow tube, which is 

 overlapped by the next crescent, the whole thus forming a tube in tube system. The 

 band is bordered by low lines and these and the direction of the stritc against it 

 distinguish it from the nearly alike keels above and below. There are three narrow 

 and prominent keels above the slit band and one beneath the same. When crossing 

 them the transverse, ornamental lines are lifted upwards and obliquely backwards, 

 more strongly in some of them, than in others. These stronger transverse lines of 

 growth are in a peculiar manner accompanied by smaller ones in the interspaces be- 

 tween the keels, diverging in an acute angle from their side or in gentle curves 

 forming with them an ovale, as is shown in the details of tigures 9 and 10. These 

 lamellate, transverse lines continue also across the suture, which is shallow, and they 

 are thus connected with the lamellae of the adjoining whorl. The surface between 

 these large ridges is finely, transversally striated. On the umbilical surface the coarser 

 striai interlace and form a sort of network, with large meshes. There is no open um- 

 bilicus, and the aperture seems to have been obovate. Height 20 millini. breadth 25 mill. 



Only one specimen froin Hammarudd in Kraklingbo. 



Divisio III. FASTIGIAT^. 



1(5. Pleurotomaria robusta n. 



PI. VIII, fig. 2—7. 



Shell globular, consisting of six liighly ventricose whorls, gradually ascending in 

 an angle approacliing more or less to a right angle, 82 — 90°. Surface nearly smooth 

 or with very fine, transverse stria- grouped in larger bands. Slit band nearly on the 

 middle line of the body whorl and near the upper suture in the other whorls. It is 

 enclosed within two fine, neatly defined lines. A little below its median line it has 

 an obtuse ridge, thus nearer to the inferior border, and the band consequently standing 

 out from the surface in an angle, the sides of which are a little concave. The ere- 



