KONfiL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 19. N:() 6. 111 



This is the large.st of the Gotlandic Pleurotoinaria', attaining a lengtli of \,m 

 decimeter and a widtli of 60 millim. The thickness of the shell nenr the urnhiliciis is 

 5 millitu. and in the body whorl of the largest specimen 6 ra. ra. 



22. Pleurotomaria Otliemensis n. 



Pl. IX fig. 14—16. 



Shell elongate, tnrricuhite, with seven ventricose whorls, wliich form an obtuse 

 angle along their median line, where the slit band is situated. This band is relatively 

 large, with convex surface, covered with regular, distantiated crescents. It is heramed 

 in by two much projecting lamellte which grow out in converging direction. The or- 

 namentation is onlj' transverse, of lamella;, with a peculiar wavy or broadly indented 

 edge. The aperture is ovate, the outer lip thin, with the broad slit in the middle, 

 the inner lip a littlc more thickened, reflexed around the narrow urabilicus. H. 34 

 mill., br. 25 raill. Apical angle 63°. It has been found in several specimens in the 

 richly fossiliferous liraestone of Samsugn in Othem. It might at first have been taken 

 for a variety of the former. But its more narrow slit band, placed on the median line 

 of the whorls, which are more angular than in Pl. valida, and its peculiar ornamen- 

 tation sufRciently distinguish it as an independent species. 



23. Pleurotomaria comata n. 



Pl. IX fig. 18—19. 



Shell regularly turbinated with seven ventricose whorls. Slit band placed on 

 the median line of the body whorl, high np near the suture on the lower whorls, con- 

 cave, with the bordering lines only slightly projecting, crescents inicroscopicallj' mi- 

 nute, crowded. The ornamentation of the surface consists in densely packed, nearly 

 straight, threadfine lines. Aperture ovate, umbilicus open, narrow. Length 9 millim-, 

 breadth 7 millim. Apical angle 64°. 



Occurs in the shale of Djupvik, from where the State Museum at Stockholm has 

 obtained several specimens. 



It is nearly related to the preceding, but differs through raore globose whorls, 

 the higher position of the slit band and the sculpture of that band, as well as that 

 of the surface. 



24. Pleurotomaria sequilatera Wahlenberg. 



Pl. IX fig. 20—29. 



Helicites ccquilaterus 1818. Wahlenberg Petrif. Svec, 73'). 



1828. Hrsmo. Anteckn. IV, 2.37. 



') The date of raost of the specifis publislied by Wahlenberg must be ehanged to 1818 instead of 1821, 

 as so often has been used. His memoir »Petrifieata Telluris Svecana» in the eighth volume of the »Aeta 



