252 PROCEEDINGS OF THE ACADEMY OF 



about as convex below as above tbe angle ; suture well denned ; aperture 

 rhomboid suborbicular, more rounded on the inner than the outer side ; outer 

 lip sharp and oblique in outline ; inner lip flattened, or somewhat furrowed 

 below, apparently for the reception of the edge of an operculum ; umbilical 

 region very slightly impressed, but not perforated. Surface ornamented with 

 strong, very regular, transverse lines, most distinct on the upper side of the 

 whorls, where they cross from the suture a little obliquely backwards, with a 

 slight forward curve, to the periphery, over which they cross iu the same 

 oblique direction, and pass on towards tbe umbilical region without any visi- 

 ble curve. 



Height, 0-41 inch ; breadth, 0-50 inch. 



This shell may be regarded as the type of a group apparently related to 

 Eolopea and Cyclonema, though it may be distinct from both. In some respects 

 it seems more nearly related to the latter group, but differs from the known 

 species of that genus, in having no traces of revolving lines. From the typical 

 forms of Holopea, it differs in having its volutions much less rounded above, 

 and more prominent or subangular around the middle, and its transverse lines 

 much more distinct. In its surface markings, and general appearance, it very 

 closely resembles Isonema bellatula (Loxonema bellatula,* Hall, Fifteenth Re- 

 port of Regents, pi. 4, fig. 4,) evidently belonging to the same group, but it 

 differs specifically in being much more depressed, or almost subdiscoidal. 



Judging from some Ohio specimens, apparently identical with Isonnna bd 

 latula, Hall, (sp.,) it seems probable that some species of this group may be 

 slightly umbilicate. 



Locality and position. White Sulphur Springs, Delaware County, Ohio, 

 Hamilton division of the Devonian series. 



Genus PLEUROTOMARIA, Defrance, 1825. 



Pleurotomaria (Murchisonia ?) META, M. & W. 



Shell rather small, conical ; spire elevated ; volutions six or seven, rounded, 

 increasing regularly and gradually from the apex ; last one slightly produced 

 below, and forming about one-third of the entire length. Suture deep and 

 well defined, in consequence of the convexity of the whorls. Spiral band flat, 

 smooth, scarcely impressed below the general surface, and placed near the 

 middle of the whorls ; one third as wide as the volutions of the spire. Sur- 

 face without revolving striae, or ridges, but ornamented by small, regular, 

 oblique costae, which in crossing the upper side of the whorls, curve grace- 

 fully backwards as they approach the band, below which they are nearly 

 obsolete and curve forward. Aperture orbicular ; columella apparently per- 

 forated by a very small umbilicus. 



Length, 0-37 inch; breadth, 0-23 inch; apical angle regular, divergence 



about 40. . ' . 



This species will be distinguished by its produced conical spire, and rounded, 

 gradually enlarging volutions, which characters give it an intermediate 

 appearance between the genera Murchisonia and Pleiirotomaria. In form it is 

 much like Pleurotemaria trilineata, Hall, but it differs from that species in 

 being entirely without revolving markings. 



Locality and position. --Warsaw, Illinois. Keokuk division of Subcaibomf- 

 erous Series. 



PTEROPODA. 



? Genus CONULARIA, Miller, 1818. 



CONULARIA MULTICOSTATA, M. & W. 



Shell with sides equal and tapering to the apex at an angle of about 22 ; 



\ 



* We cannot believe these forms can be properly included in the genus Loxonema, as restricted 

 to such shells as the typical Terebra sinuosa, of Sowerby. 



[Dec 



