112 TRANSACTIONS OF THE WAGNER FREE 



belief that Conrad's determination is the correct one. The two forms 

 are certainly most intimately related, despite Gabb's assertion to the con- 

 trary ; the Mississippi fossil has a somewhat higher spire, and a more 

 thickened outer lip, but these distinguishing characters may belong 

 exceptionally to the single individual which in the Philadelphia collection 

 represents Conrad's species. 



Natica amphora, nov. sp. Fig. 50. 



Shell semi-globular, depressed on the basal surface; spire elevated, 

 of about four volutions, all the whorls deeply channeled along the 

 sutural line ; body-whorl about three-fourths the size of the entire shell ; 

 aperture semi-lunate, contracted above, effuse below ; inner (columellar) 

 border of aperture direct, diagonal ; deposit of callus considerable, 

 leaving a long, narrow umbilical fissure; base of shell sub-carinated ; 

 surface smooth. 



Length, about four inches ; greatest width, across the centre of 

 aperture, 3.7 inches. 



This species, the largest of the American fossil Naticas, cannot be 

 readily confounded with any of the hitherto described members of the 

 genus. Although in a general way recalling the recent N. diiplicata, it 

 is immediately distinguished from that form by the deeply impressed 

 sutural-line and the exposed umbilicus. Its nearest ally appears to be 

 N. maxima, Grateloup, from the deposits of Bordeaux and Dax, France, 

 but it lacks the peculiar expansion of the body-whorl of that species, and 

 further differs in the exposed umbilicus. 



Amaura Guppyi, Gabb. 



Trans. Am. Philos. Soc., xv ("Topography and Geology of Santo Domingo"), p. 224. 



Identified by a single specimen. 



Natica streptostoma, nov. sp. Fig. 51. 



Shell depressed, oblique, with the spire almost concealed ; aperture 

 very large, sigaretiform, the border flattened on the columellar side, and 

 folded over into a pseudo-carina, which passes beneath the labium as the 

 outer bounding-line of the umbilicus ; umbilicus narrow, vertical ; surface 

 smooth. 



Length (height), one inch ; greatest width, diagonally across the 

 apertare, 1.2 inch. 



May be readily identified by the large, oblique aperture, and the basal 

 carina. 



Turritella pagodaeformis, nov. sp. Fig. 52. 



Shell gently elevated, gradually tapering ; whorls numerous, hollowed 

 medially, with an expanded base, which projects considerably beyond the 



