176 G. LINDSTROM, on the SILURIAN GASTROPODA AND PTEROPODA OF GOTLAND. 



Several specimens found in the limestone of the hills at Sandarfve and Linde. 

 Besides its size and shape this species is distinguished from the nearly allied C. 

 delicatulum throuo^h its ornamentation, which is different as to its direction and size. 



4. Cyclonema distans n. 



PI. XVIII fig. 37. 



Shell small, turriculate, of iive whorls, of which the body whorl is nearly as 

 high as the spire. There are eighteen sharp, distinct, distantiated keels and the trans- 

 verse lines which intersect them are also distantiated but narrow. They are directed 

 slightly backwards, but cunverge on the umbilical side. H. 8 mill., br. 6 mill. 



Only a single specimen has been found in the limestone of the hill of Sandarfve. 



5. Cyclonema striatum His. 



PI. XVII fig. 48, pi. XVIII fig. 39—42. 



Turbo striatus 1837. Hisinger Anteckn. VI, 109. pi. VIII f. 2. 



1837. Id. Lethiea, 38, tab. XII fig. 5. 



1840. Id. Forteckn., 55. 



1867. LiNDSTR. Nomina, 23. 



Turbo Leda 1850. D'Orb. Prodr. I, 30. 



Turbo striatus 1877. Krause Zeitschr. d. deutsch. Geol. Gesellsch., 23, can only with doubt be referred to 

 this genus. 



Shell turbinate, with six ventricose whorls, suture deep and immersed; there are 

 only spiral, closely set lines, which vary in their distance from each other, but gene- 

 rally leave an interstice smaller than themselves. Around the umbilicus they are more 

 distant and more prominent. The last whorl is free near the aperture, which is quite 

 circular without any reflexed lips, which are sharp all around. The original specimen 

 of Hisinger is figured here anew; it is fragmentary and the revolving lines are more 

 distant than in other specimens. In his collection there are two specimens thus de- 

 nominated, the smaller one is only a cast without shell from the shale of Hogklint. The 

 larger specimen, the figured one, is from Klinteberg and the Palseontological Museum 

 also has specimens from that locality as well as from Ostergarn, Samsugn in Othem 

 and the shale beds of Wisby. H. 16 mm., br. 14 mm., diam. of the aperture 6 mm. Turbo 

 corallii Sow., and Trochonema pauper Hall 20:th Rep. p. 343, pi. 15 f. 5, 6 (= Cyclonema 

 pauper Hall 20:th Rep., Docum. Ed. p. 395 pi. 15 f. 5, 6) come near to this shell. 

 The largest specimens somewhat resemble smaller specimens of Or. globosura or sculp- 

 tum. The narrowness or total Avant of any umbilicus, the elevated spire of rounded 

 whorls, the circular, nearly free aperture, however, distinguish them sufficiently. 



From the limestone of Samsugn a specimen has been obtained with an oper- 

 culum in reversed position in its aperture. It has no doubt belonged to the shell. 



