KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 19. N:0 6. 129 



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

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

 Fårö, and some specimens from Wialmsudd 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, biit this may on 

 closer inspection and coraparison be traced to changes after the fossilization. These 

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



5. Murcliisonia subplicata n. 



Pl. XII fig. 8. 



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

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

 is placed. The inferior börder 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 nmbilicus a narrow fissure. 



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



In all, six specimens have been obtained from Lummelund in the superior limestone. 



6. Murchisonia compressa n. 



Pl. XII fig. 15—19. 



»Turritella? (Turbo L.)» 1828. Hisinger Anteckningar IV, 221, tal). VI f. .3. 



Turrilella cmgulata 1831. Id. p. p. Anteckn. V, 115, tab. II f. 1 (nucleus). 



18.37. Id. p. p. Lethrea Suec, 39, tab. XII fig. 6 b. 



»Stenkärnor af Turriteller» 1841. Ii). Förteckning, 56. 



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 foUow- 

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



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



Two specimens. 

 Spec. A. Spec. B. 



Height of whorls. Bieadtli. H. Br. H. Br. H. Br. H. Br. H. Br. 



Body whorl 17 mm. 31 ram. 12 mm. 22 mm. 9 mm. 20 rara. 17 mm. 20 mm. 18 mm. 22 rara. 7 mm. 11 mm. 

 .2 .'. 12 » 25 » 10 « 19 » 8 » 18 » 12 » 15 » 17 » 18 » G » 9 » 



3 — 10 » 18 » 8 » 15 » 7 » 17 » 10 » 12 » 12 » 14 » 4 » 8 » 



4 7 » 14 » — — 7 " 15 » 6 » 10 » 9 » 11 » 3 » 6 •> 



5 — — — — G » 13 » 5 » — G » — 3 " 5 » 



6 — — — — 5 » 12 " — — — — 2 » 4 » 



7 — — — — 5 » 10 » — — — — 2 » 3 B 



8 — — — — 4» 9» — — — — 1»2» 



9 — — — — 4» 8» — — — — — — 



10 — — — — 3" 7» — — — — — — 



11 — — — — 3» 6» — — — — — — 



12 — — — — 3» 6» — — ___ — 



K. Vet. Akad. H.-indl. Band 19. N:o fi. 



17 



