122 



o. LIND.STRÖM, ON THE SILUTIIAN GASTROPODA AND PTKROPODA OF GOTLAND. 



is deepened, and thence having a pitted aspect. The aperture is obliquely elliptical, 

 broader than high. The lips seem to have been thin, not reflexed. The umbilicus is 

 open and wide and all whorls are visible inside. 



Height 55 inill., breadth l,i decira. Body whorl near the aperture 52 mill. across. 



About eight specimens of this large shell have been found in the lower litne- 

 stone strata of östergarn and a smaller in the uppermost limestone of Linde klint. 



As the specimens found are mostly nuclei and only few traces or shreds of the 

 shell are left, there may be some doubt if this species belongs to Pleurotomaria. 15ut 

 the direction of the transverse strire seem to warrant such a supposition, even if there 

 is no certain evidence in the section of the very thin slit band lamella, pl. XI fig. 28. 



Divisio VII. PLANORBIFORMES. 



37. Pleurotomaria planorbis Hisinger. 



Pl. XIX fig. 30—39. 



Turhinites centrifugus 1828. 

 Helieites? centrifugus 1828. 

 Éuomphahts centrifugus 1829. 



1831. 



1831. 



1848. 



1854. 



1855. 



1867. 



1873. 



1876. 

 Euomphalus substriatus 1829. 



1831. 



HrsiNGEU (not Wahlenbeeg). Anteckn. IV, 221, 237, tab. VI f. 2. 



Id. Ibid. in the explan. of the figures. 



Id. Tableau, ed. 1, 10. 



Id. Anteckn. V, 114, tab. 1 fig. d. 



Id. Tableau, 9. 



Bronn. Nomenlator, 478. 



MoKRis. Catal. Brit. Foss. Sec. Ed., 247. 



Mac Coy. Palseozoic Fossils, 297. 



Salter, Siluria, 231, 531. 



Id. Catal. Cambr Foss., 156, 172. 



Ferd. Roemer, Lethrea Geogn. Taf. 14 f. 13. 



Hisinger Tableau ed. 1, 11. 



Id. Anteckn. V., 114. Tab. 1 fig. e. 



Id. Tableau ed. 2, 9. 



Hisinger, according to Bronn Leth. geogn. 



Bronn Nomenclator, 256. 



His. Lethaea Suec, 38, tab. XII f. 1 a— c. 



Id. Förteckn., 55. 



LiNDSTR. Nomina, 29. 



Qdenstedt Petrefaktenkunde Deutschlands le Abtheil. 7i- Bd., 395, tab. 200 



fig. 81. 

 D'Orbigny Prodr., 30. 



Shell disciforra, with tive whorls, rapidly increasing in size in the following ratio. 



Body whorl 22 mill., in breadth. 



Centrifugus planorbis 

 Inachus sulcatus 



1831. 

 1835. 

 1848. 

 1837. 

 1841. 

 1867. 

 1882. 



Straparollus sulcatus 1850. 



Ed. 1, Bd. 1, 97. 



2 

 3 

 4 

 5 



11 

 5 

 3 

 2 



The slit is at first large and broad and forms, where it ends, a narrow, acute 

 angle. It, as well as its continuation, the slit band, is situated on the apical side of 

 the shell, close to the suturc as in the following species. It is coinparatively nar- 

 row, elevated above the surface as a thin string and included only by the straight ed- 

 ges of the shell, though in a few instances there are obscure traces of bordering lines. 



