KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 19. N:n 6. 129 



The typical specimens are derived from the limestone beds of Kyrkberget (Rackar- 

 backen) in Wisby. Others are from Lummelund, Samsugn in Othem, Lutterhorn in 

 Faro, and some specimens from Wialmsndd may perhaps also belong here. Those 

 from Samsugn, fig. 11 — 12, are much altered through corrosion and in some there is 

 a false appearance as if the slit band were lineated longitudinally, but this may on 

 closer inspection ami comparison be traced to changes after the fossilization. These 

 specimens, however, are somewhat less angular than those from the other localities. 



5. Murcliisonia subplicata n. 



PI. XII fig. 8. 



Shell short and thick in comparison with its congeners. Whorls nine, slowly 

 increasing, widened on the middle into an obtuse ridge where tlie shallow slit band 

 is placed. The inferior border of the whorls is folded into a callous ridge, which 

 overlies and partially covers the deep and narrow suture. The aperture is ovate, the 

 inner lip reflexed and the umbilicus a narrow fissure. 



Height 27 millim., breadth 21 mill., apical angle 35 °. 



In all, six s^jecimens have been obtained from Lummelund in the superior limestone. 



6. Murchisonia compressa n. 



PI. XII fig. 15—19. 



oTnrriteUaf (Turbo L.y> 1828. Hisinger Anteckningar IV, 221, tab. VI f. 3. 



Tiirrilelkt cingulala 1831. In. p. p. Anteckn. V, llf), tab. II f. 1 (nuclinis). 



1837. Id. p. p. Lethnea Suec, 39, tab. XII fig. G 1). 



»Stoiikiiiiior af Tiirritellor» 1841. Id. Forteckning, .50. 



Shell elongately turriculate, with slowly tapering whorls, only moderately ven- 

 tricose, numerous — as many as 18 have been numbered in one specimen. The ratio 

 of the increase in the whorls is in this species much slower than in any other, the 

 breadth augmenting much faster than the height, as is made evident through the follow- 

 ing comparative table of the dimensions of the whorls in five species. 



M. cingulata. M. cava. M. compressa. M. attenuata. M. obtusangula. 



Two specimens. 

 Spei-. A. Spec. B. 



Height ufivhorls. Bicadtli. II. Hi'. II. Br. II. Br. IT. Br. IT. Br. 



I?0(ly whorl 17 mm. 31 mm. 12 mm. 22mm. 9 mm. 20mm. 17 mm. 20mm. IS mm. 22 mm. 7 mm. 11mm. 



2 .'. 12 » 25 » 10 » 19 » 8 » 18 .. 12 » 15 « 17 -> 18 » C » 9 » 



3 10 » 18 n 8 » 15 » 7 » 17 " 10 » 12 » 12 " 14 » 4 » 8 » 



4 _ 7 1) 14 " — — 7 " 15 " (5 » 10 " 9 " 11 » 3 » 6 » 



— — C » 13 » 5 » — G » — 3 " 5 » 



6 — — — — 5 » 12 - — — — — 2 » 4 



7 — _ — — 5 » 10 » — — — — 2 » 3 



8 — — — — 4b 9 » — — — — 1»2 



9 — — — — 4"8)> — — — — — - 



10 — — — — 3»7» — — — — — 



11 — — — — 3»6.. — — — — — 



12 — — — — 3„6»— — — — — 



K. Vet. Akad. Haiull. Band in. N:o fi. 



17 



