KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 19. N:0 6. 155 



extant so much weathered, that no sculpture can be discerned, excepting some indistinct, 

 crescent formed transversal lines. Along the upper border of the whorls a narrow, 

 slightly elevated string is seen, being the uncovered portion of the acuminate ridge, 

 that divides the apical side from the umbilical. The later is almost flat. The aper- 

 ture is transversally elliptical and the umbilicus wide, surrounded by the elevated cal- 

 losity, which emanates from the thickening of the inner lip. H. 28 millim.; br. 32 

 mill. Only one specimen is known, belonging to the collection of the school of Wis- 

 bj-, derived probably from the upper limestone near that town. 



Fam X. TURBINIDiE Alder. 



In following the precedence of S.P. Woodwaud ') and partly also of Zittel^) I 

 place the following five genera within this family. Some of the shells, which I have com- 

 prised within the genus Oriostoma, have by Deshayes and most authors after him been 

 numbered with the Solariidaj. One of the latest authors, Stoliczka^), does it on account 

 of the presumed similarity of its operculum to that of Torinia and the more so to 

 that of Omalaxis, with which recent genus also some of the palasozoic forms have been 

 regarded as identical. But besides, that nearly similar forms of opercula also occur in 

 other families, as the Siliquaria^, the Vermetida; and the Turritellidaj, there is another 

 circumstance which makes it probable that the palaeozoic shells under consideration 

 cannot belong to the Solariidas. It consists namely in the important feature that se- 

 veral of its species have retained the most evident traces of a nacreous layer, both in 

 the genus Oriostoma as well as in Cyclonema. Moreover the operculum is solid and 

 shelly not chitinous as in the former genera. These genera, which thus closer agree 

 with the Turbinidfe than with the Scalariidae are the following. 



Oriostoma Munier-Chalmas, with short spire, surface richly ornamented by lon- 

 gitudinal carinte, crossed by variously sculptured, transverse striae. Operculum conical, 

 solid and shelly with narrow coils. Umbilicus large and open. 



Cyclonema Hall, with .high spire, ornamentation of fine, slightly prominent lon- 

 gitudinal keels, crossed by equally fine, transversal stria?. Operculum depressedly coni- 

 cal with large coils and hollow inside. No umbilicus or a very narrow one. 



Trochonema Salter, turbinate, whorls angular through several distantiated sharp 

 keels, umbilicus large, open. 



Eunema Salter, small, turriculated, with one or several narrow keels and other 

 sculpture, umbilicus closed. 



Craspedostoma n. gen., shell globose, naticoid, with the lips widened to a broad 

 frame around the aperture, lower end of interior lip enlarged into an aliform appendix. 



') Manual of Moll. 2d Ed. 263. 

 -) Handb. PalEeont. 1,2, 187. 

 ^) Paloeontologia Indica V, 249. 



