KONGL. SV. VET. AKAEMIENS HANDL. BAND. 19. N:0 6. 179 



Shell turbinate, acuminate, with six ventricose whorls, the five inferior whorls 

 with two sharp keels each. On the body whorl there are a variable number of 8 or 

 10 keels of which the lowest two are largest and most prominent, the most inferior 

 leaving a larger zone between itself and the suture than the space to the next keel. 

 There is also a low keel near the suture. The surface between the keels is tinely and 

 transversally striated by dense, obliquely backwards slanting streaks. The aperture is 

 almost ovate, higher than broad and the umbilical opening is narrow, being in some 

 specimens covered by the inner lip, which is reflexed towards the columella. H. 30 

 millim., br. 25 mill., height of aperture 15 mill. 



It has been found at Djupvik in Eksta, Samsugn in Othem, north of Skaret in 

 Frojel and at Follingbo, Slite and Petesvik in Habblingbo. 



8 a. Cyclonema carinatum Sow. var. glabrum n. 



Shell small, turbinate, acuminate, five ventricose whorls with three or four lon- 

 gitudinal, distantiated keels on the apical side of the body whorl. They are entirely 

 wanting on the umbilical side which is almost smooth, only ornamented with the 

 same sort of faint, transverse strise as on the apical side. Around the umbilical cavity 

 a short, sharp ridge starts from the upper edge of the aperture, which is obovate, 

 acuminate below. The umbilicus is narrow. H. 8., br. 6 mill. It has been found toge- 

 ther with the typical specimens in the shale of Djupvik in Eksta. 



8 b. Cyclonema carinatum Sow. var. multicarinatum n. 



PI. XVIII f. 31—32. 



This differs chiefly from the main species through the numerous and small lon- 

 gitudinal keels, the nearly circular aperture and the large and open umbilicus. The 

 keels arc as many as 14 on the body whorl and from five to seven on the whorls next 

 in size. On the body whorl the keels are more distantiated a little above the suture. 

 As many forms connect it with Cyclon. carinatum, forma typica, there is no cause to 

 represent it as a species of its own. H. 19 mill., br. 17 mill. Several specimens have 

 been obtained from the shale of Djupvik in Eksta. 



9. Cyclonema nodulosum n. 



PI. XVIII fi^. 33—35. 



Shell variable with long or short spire, with deeply impressed suture, whorls six, 

 nearly disjointed, as seen by section fig. 35, with 8 — 10 distantiated keels. It differs 

 from Cycl. carinatum in the peculiarity that the transverse oblique stria? at regular 

 distances are more elevated than the others, and where they cross the keels, they form 

 a small tubercle or nodule through which the surface acquires a retiform aspect. All 

 specimens have a wide umbilicus and the axis is hollow. The aperture is circular with 

 thin lips and almost free from connection with the next whorl. H. 20 mill., br. 16 

 mill. It has hitherto been found only in the shale of Djupvik in Eksta and Frojel. 



