248 G. LINUSTIJÖM, ON TIIK SILURIAN GASTROPODA AND l'TER(ir01)A OF GOTLAND. 



Plate XXI. 



Fiff. 



1— 3. 



4—10. 

 11—14. 

 15—19. 

 20—29. 



.SO— 34. 

 35—38. 

 39—42. 



43—54. 



55—56. 

 57—60. 

 61—65. 

 66. 



Murcliisonia paradoxa n., p. 131. 



Oriostoma nitidissiniwn n., p. 173. Fig. 4 — 7 from Sandarfve, f. 8 — 10 from Follingbo. 

 » dispar n., p. 173. 



Trochonema turritum n., p. 181. 



Craspedostonia elegantulum n., p. 183, f. 20 — 24 from Samsiign, f. 25 — 26 from Slite, f. 

 27 — 28 from Follingbo, f. 29 from Klinteberg. Fig. 23 part of the surface enlarged, the 

 left side covered with rock as coramon, the transversal rlbs only visible; f. 24 transversal 

 section of the columellar lip, where it is bifid, f. 26 part of the surface; in the inferior 

 figure the lighter, wavy parts between the darker, broken edges of the trausverse ribs are 

 formed by calcareous mud on which are seen impressions of the now missing, backwards 

 reflexed edges of the ribs. The npper figure, a longitudinal section of the inferior one, 

 elucidates this, the dark portions being the shell and the curved ribs, their continuation 

 marked by dotted lines, the light mud filling the interspaces. 



Craspedostoma brevispira n., p. 183. Fig. 32 surface partly covered by rock, partly free. 

 » filistriatum n., p. 183. 



« involutum n., p. 184. Fig. 42 transverse section of columella, showing hovv it is 



bifid as in the other species. 



» glabrum n., p. 184. Fig. 49 section across the outer lip and partly across the 



body whorl. The superior branch being the lip, the inferior one the shell, the inside of the 

 aperture being to the right. 



(Jyclonema perversuvi n., p. 180. 



Autodetus calyptratus Schrenk, p. 185, young specimens. 



Onychocldlus reticulatum n., p. 196. 



Cyclonema sp. indet. operculum from Westerbys in Ardre, p. 177. 



