GASTEROPODA. 47 



LOXONEMA DELPHICOLA. 

 PLATE XIII, FIGS. 19-25, AND PLATE XIV, FIGS. 1, 2. 



Loxoiiema delphlcola, Hall. Descriptions of New Species of Fossils, etc., p. 24. 1861. 



Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 52, pi. 4, f. 9. 1862. 

 " " Illustrations of Devonian Fossils: Gasteropoda, plates 13 and 14. 1876. 



Shell turretiforra ; spire somewhat rapidly ascending. Volutions eight or more 

 in the entire shell, flattened upon the sides, the last one slightly ventri- 

 cose. Aperture ovate, narrowed and attenuated at the base ; columella 

 thickened and extended below. 



Surface marked by strong, not prominent, longitudinal stria?, which are bent 

 slightly back for a short distance below the suture, and continue in a 

 nearly direct or slightly curving line almost to the base of the volution, 

 where they bend forward to the suture-line. Suture banded, or the upper 

 edge lit' the volution overlapping the next preceding, and constricted just 

 below the margin, which is but faintly or not at all marked by the longi- 

 tudinal stria'. 



This species differs from the more common form of the Loxonema of the 

 Hamilton group in the lesser convexity of the volutions, and more rapid expan- 

 sion from the apex, straightness of the stria? (which, however, are more 

 abruptly bent on the last volution) and the overlapping or banding of the upper 

 margin of the volution at the suture-line. One specimen examined retains 

 nearly six volutions, and has a length of one inch and a half, which would 

 have been slightly increased, had the lower extension of the columella been 

 entire ; diameter of last volution a little more than half an inch. A specimen 

 of the ordinary form (L. Hamiltonm), possessing six full volutions, measures one 

 inch and a quarter in length; the six volutions, from the aperture reaching to 

 the height of the fourth volution in the species under consideration. In the 

 ordinary flattened or crushed condition of these fossils, as they occur in the 

 finer shales of the group, the distinction between the two species is not always 

 easily recognized. 



Formation mid hcaMe*. In shales of the Hamilton group; Delphi, Onondaga 

 county, Bellona, Yates county, and shores of Cayuga lake, N. Y. 



