148 G. LINDSTRÖM, ON THE SILURIAN GASTKOPODA AND PTEROPODA OF GOTLAND. 



Several specinieiis have beeii obtained from Klinteberg and Samsugii, uiid also 

 from Kyrkberget in Wisby. 



It reminds, as to the ornamentatioii, of Troclius Gotlandicus, but tbe traiisverse 

 strJLU are more straight in tliat species and sigmoid in Tr. Stuxbergi, moreover the 

 umbilical side and the shape of the whorls is quitc different in both. 



5. Troclius undulans n. 



Pl. XVI fig. 8—10. 



Shell small, obtusely conical of five tumid whorls, bulging out near their inferior 

 part and with the sides above straight and vertical, whence the body whorl acquires 

 a cup shaped appearance or also they are of a concave outline, fig. 8. The oblique, 

 transverse lamella3 of growth are distantiated, and have their projecting edges rauch 

 wavy and folded in a great number of sinuosities, quite peciiliar to this species. The 

 umbilical side is nearly flat, in the centre excavated into a deep funnel, on the bottom 

 of which the opening of the narrow umbilicus is seen. The horizontal ridge which 

 all around borders this siirface is thin and wavy. The aperture is circular, enclosed 

 within thick lips, the outer one being especially large and in its uppermost corner 

 angulated. 



H. 8 milL, br. 12 mill. 



Only three specimens have beeu found, two from the upper limestone beds of 

 Slite aud the third from Samsugn in Othem. 



6. Troclius profundus n. 



Pl. XVI fig. 11—13. 



Shell of moderate size, broadly conical with large periphery of the umbilical side 

 and short spire. Six whorls of somewhat concave contour. The ornamentation con- 

 sists of oblique, transverse striaä or rather steplike gradations following each other at 

 wider distances than the strise in the preceding species. When seen in a section, 

 cuttiug thera transversally they have a serrated appearance. The umbilical side is quite 

 smooth and glossy, excavated or cup-shaped, through the large, very thin, upwards 

 directed borders, which encircle the upper side of the whorls and the aperture. This 

 is circular and lies at some distance inside the börder of the shell. A 

 shallow, curved groove in direct continuation with the aperture, indicates 

 the place the animal occupied when prc)truding itself from the shell. 

 orfro"h'uTprofuu-" The outcr lip is thin and sharp, the interiör one thicker and straight. 

 dus, natiirai size. -pi^y uuibilicus is opcD and widc; the axis is open as seen in the annexed 

 woodcut. H. 13 mm., br. 16 mm. 



Two specimens have been found in the limestone of Samsugn in Othem. In 

 this, as well as in the following species and Tr. Stuxbergi and Tr. undulans, the 



