242 G. LINDSTKOM, ON THE SILUHIAN GASTROPODA AND PTEROl'ODA OF GOTLAND. 



Plate XVIII. 



Fig. 1 — 2. Tnjblidium. radiatum n., p. 58. 

 » 3 — 6. Loxonemai altenuatum n., p. 143. 

 1) 6 — 8. Euomphalus tuba n., p. 140. 



» prcecursor ii., p. 140. 



« Walmstedti, n., p. 141. 



Trochus eavus n., p. 149. If not rather au Onustus? 

 » gyrans n., p. 152. 

 » densestriatus n., p. 152. 

 Oriostoma globosum Sow. p. 161. Microscopic section of two coils of the operculum. 

 Cyclonema cancellatum n., p, 175. 

 » carinatum Sow., p. 178. 



i> carinatum, var. glabrum n., p. 179. 



» carinatum, var. multi carinatum n., p. 179. 



M nodulosum n., p. 179. 



» apicatum n., p. 175. 



» distans n., p., 176. 



» tenuissimtim n., p. 180. 



» striatum His., p. 176. Fig. 39 is from the original of Hisinger, preserved in the 



State Museum at Stockholm. Fig. 41 — 42 from Samsugn. 

 Cyclonema zonatum n., p. 178. 

 Holopea perforata n., p. 188. 

 46 — 47. Macrocliilina cancellata n., p. 191. 

 48 — 49. i> bulimina n., p. 191. 



50 — 51. Pleurotomaria Wisbyensis u., p. 100. 

 52 — 53. Trochonema muricatum u., p. 181. 

 54 — 57. Onychochilus cochleatum n., p. 197. 

 58 — 59. ^ubulites ventricosus p. 193. 

 60 — 61. » ventricosus, var. curvus n., p. 194. 



62. » attenuatus n. p. 194, transverse section. 



63 — 64. Daphiiella limncBiformis L. Recent, to compare with the aperture of Subulites and Euchrysalis, 



f. 63 transverse section. 

 65 — 68. Euchrysalis iineolata n., p. 195. 



69. Turritella sp. Recent, transverse section to compare with those of the preceding shells, showing 



the dissimilarity in holostomous and siphouostoraous shells. 



