PTEROPODA. 



The fossil remains of the Upper Silurian Pteropoda of Gotland are by no meuns 

 so common nor so characteristic of several beds, as are those of the Gastropoda. As 

 I do not consider the Tentaciilites as Pteropods in consequence of their close affinity 

 to the fixed Cornulithes and similar, there is only one genus known. 



Gen. CONULÄRIA Miller. 



1818 Miller in Sowerby's Mineral Conciiology III. p. 108. 



Shell pyramidal, extremely thin, of several strata, each of these homogenous and 

 transparent, broum or red; near the initial aj)ex the shell is partitioned off by a transverse 

 diaphragina. Apex often deciduous. Aperture narrow, partially dosed by tonguelike prolon- 

 gations from the corners. Side corners grooved or blunt. Along the middle of each face 

 there runs from the aperture to the apex one or in some species two folds, which project 

 only a little distance inioardly. In others they are totally wanting or represented by one or 

 two longitudinal septa placed on the inner side. Surface ornamented by transverse ridges, 

 smooth or tuberculated, forniing an obtuse angle along the median line of the surface loith 

 its apex directed toivards the aperture. 



The systematic place of this genus and its allies has long been subject to some 

 discussion and difference of opinion. Among the various opinions on the nature of 

 Conularia raay be annotated that it was ranged with the Cephalopoda by J. Sowerby, 

 Beonn, F. a. Roemer, Blainville, G. B. Sowerby, Fleming, Hoeninghaus; this may 

 partly have been occasioned by a false appearance of a siphuncle in the diaphragra, 

 of which Hall still speaks as present in his Conularia trentonensis. D'Archiac and 

 Verneuil seera to have been the first who considered Conularia as a Pteropod and they 

 were in this view followed by D'Orbigny, Morris, De Koninck, Leonhard, G. Sandberger, 

 AusTiN and almost all låter naturalists. 



HiECKEL again, in his Morphologie vol. II, page cxiii, denies that the Conularia3 as 

 well as the other pala^ozoic fossils hitherto presumed to be Pteropods belong to thatgroup 

 of Molhisca and he thinks that no true Pteropods are found in a fossil state anterior to 



