NATURAL SCIENCES OF PHILADELPHIA. 447 



rather deeply sinuous on the upper inner side, for the reception of the pre- 

 ceding whorl ; lip oblique, produced above and retreating below, somewhat 

 distinctly reflected, particularly on the under side ; surface marked by well 

 defined lines of growth, which cross the upper side of the whorls obliquely. 



Height, 0-90 inch; greatest breadth, 1-83 inches; breadth of aperture, 

 - 74 inch ; height of do., 072 inch. Apical angle convex, divergence about 

 120. # 



This fine large Helix will be at once distinguished by its size and general 

 form from any other species yet known in the Nebraska rocks. Some twelve 

 specimens of it were obtained, all of which are in the condition of internal 

 casts. One or two of them retain some fragments of the shell, which are 

 marked by strong lines of growth ; none of the specimens, however, are suffi- 

 ciently well preserved to show whether or not there were any fine revolving 

 striae. From impressions left on the matrix, the aperture seems to have been 

 a little constricted on fhe under side, but none of the specimens are in a con- 

 dition to show whether or not the lip was much thickened. 



Amongst recent species it may be compared with the Chilian H. laxata of 

 Furisac, from Coquimbo, with which it agrees in size and form, though its 

 umbilicus is proportionally a little smaller, and it has about one whorl more. 

 All its volutions are likewise less rounded on the under side, while its lines 

 of growth are much stronger. The most nearly allied North American living 

 species is H. Newberryana of W. Gr. Binney, a California species, from which 

 it will be readily distinguished. 



Locality and position. Wind River Valley. From Wind River Group. 

 Tertiary. 



Helix veterna. 



Shell of about medium size, obliquely oval and subrhombic in outline ; 

 volutions five and a half, increasing rather rapidly in size, those of the spire 

 moderately convex ; last one comprising about half the entire length, most 

 convex below the middle, rounded on the under side, and somewhat obliquely 

 produced below ; umbilicus small or closed ; suture distinct, but not very 

 deep ; aperture ovate, rather narrowly rounded below, and somewhat obtusely 

 angular above, slightly modified on the inner side above, by the convexity of 

 the preceding whorl ; lip reflexed ; surface marked by distinct, oblique, 

 threadlike striae. 



Height, 1-24 inches; breadth, 1-05 inches; height of aperture, 0-75 inch; 

 breadth of do., 0*57 inch. Apical angle very convex, divergence, S5 to 90. 



This species is about the size, and presents much the appearance of H. 

 Leidyi Hall & Meek, (Mem. Am. Acad. Arts and Sci. Boston, vol. v., n. s., p. 

 394, pi. 3, fig. 12 a b.) It is a more elongated shell, however, and its spire 

 is a little more elevated, while its body whorl is more produced below. Its 

 aperture is also quite different, not being near so oblique and more extended 

 below. 



Locality and position. Same as last. 



CORRECTION. 



In printing our Catalogue of Nebraska Fossils, in the October number of 

 the Proceedings for 1860, the family name ARCAD2E was inadvertently 

 omitted on page 428, between the names Inoceramus Balchii and Area sulcata, 

 which makes it appear as though we were intending to place the genera Area. 

 Cuculhva, Axinasa and Linopsis in the family AVICULID-S! 



1861.] 



