/, 



^■ 



84 



and the saddle of the interior lip is large. The keel is blunt to judge by the cast 

 of it. Height of the shell l\3 niillini., breadth 23 milliin. Height of aperture 20 niil- 

 lim., breadth of same 15 millini. 



Only one specimen has hitherto been found in the limestone of Martebo. 



4. Cyrtolites olbliquus n. 



PI. VI figs. 54—55. 



Shell discoid, a little obliquely involute, terete; ornamental stride most minute, 

 closely set, with denticulated edges, dorsal carina blunt and narrow. Whorls three and 

 a half. Diameter of the fragmentary shell 3 millims. From the sandstone of Bursvik. 



5. Cyrtolites euryomphalus n. 



PI. VII figs. 10-15. 



Shell discoid, involute, sui-face smooth, rather glossy, ornamented with regularly 

 distanfiated lines, elevated, giving the surface an imbricated appearance. Along the 

 interior edge of the wlioi'ls there runs a narrow ridge, on which the transverse lines 

 swell in a minute nodule. From this ridge the surface falls off abruptedly towards 

 the centre of the shell. The whorls are four and a half, gradually increasing in width, 

 contiguous. The aperture is broader tlian long, nearly pentagonal, with the dorsal ca- 

 rina forming a tonguelike processus from the supei'ior edge. The slit band is much 

 prominent, flat on its outer edge and covered with distaiitiated, ci'escent shaped lines 

 of growth. Diameter 5 millim., breadth of aperture 3 millim.; heiglit 2 millim.; dia- 

 meter of space enclosed within the interior ridge 2 millim. F>om the shale at Djup- 

 vik in Eksta. Some twenty specimens known. A corroded specimen has also been obtained 

 from the sandstone of Bursvik. 



6. Cyrtolites discus n. 



PI. VII tigs. 18—21. 



Shell discoid or lenticular, slightly tumid, surface with linear, elevated, trans- 

 verse stria?, curved gently backwards on the dorsal side, regularly distantiated and hav- 

 ing between tliem much finer, minute lines. Whorls four, gradually increasing, the 

 last one partially free. Aperture triangular, lower lip nearly straight, horizontal, lateral 

 margins faintly curved, converging at the narrow dorsal slit. Slit band narrow, eleva- 

 ted, blunt, not much prominent, covered with small crescent sliaped lines of growth. 



Largest diameter 7 millim., breadth 3 millim. 



The original specimen, which belongs to the Museum of the Geological Survey 

 of Sweden, has been found in the sandstone of Bursvik. Later, another specimen has 

 been found in the middle limestone beds near Wisby. This is more smooth without 

 any smaller lines between the large transverse stria;. 



