INSTITUTE OF SCIENCE, PHILADELPHIA. 71 



Columellar surface broad, slightly flattened, completely covered by 

 the thin labium ; aperture about two-thirds the length of shell, or less, 

 quadrangular, broadly-open. 



Length of largest specimen, somewhat more than four inches; greatest 

 width, over the shoulder angulation, 2.7 inches. 



Caloosahatchie, in the banks below Fort Thompson. 



This species closely resembles the recent Melongcna corona of the 

 southern coast, and, at first sight, can be readily mistaken for it. But it 

 differs in the greater elevation of the spire, the obtuseness of the shoulder 

 angulation (shoulder concave in M. corona), the much smaller number of 

 spines, both on the superior and inferior carinations, the nature of the 

 spines or tubercles, which are much more nearly closed (less scaly) in 

 M. snbcoronata, and in the circumstance that the shoulder spines are 

 directed outward, and not upward and inward, as we find them in M. 

 corona. 



Fulgur rapum, nov. sp. Fig. 4. 



Shell pyruliform, closely inwound, with a short depressed spire ; 

 whorls of the spire about five, gently crenated basal ly (or above the 

 sutural line) ; apex papillate. 



Body-whorl ventricose, high, convex, sub-angulated above, and to an 

 extent also inferiorly, somewhat nodulose on the rounded shoulders ; 

 neither true tubercles nor spines ; tendency to nodulation in some cases 

 entirely wanting; aperture of nearly the entire length of the shell, 

 elliptical above, and produced into a long, narrow, straight canal, which 

 is slightly deflected to one side; outer lip strongly lined internally. 



Columella arcuate, rapidly contracting the aperture at the beginning 

 of the canal ; columellar fold not very prominent. The entire surface of 

 the shell covered with closely-placed, moderately elevated, revolving striae, 

 which have a gently sinuous outline, and exhibit a distinct alternation 

 of coarser and finer lines. 



Length, 6.5 inches ; width, 3.5 inches. 



In the banks of the Caloosahatchie, below Fort Thompson. 



None, of the recent species of Fulgur at all approach this shell, and 

 even among the fossil species there is none from which it cannot almost 

 immediately be distinguished. The species that most nearly resembles it 

 is undoubtedly the form figured by Conrad on pi. 47 of his Medial 

 Tertiary Fossils (1839) as F. maxiimis, which has apparently never been 

 described. The ornamentation of this shell is practically identical with 

 that of F. rapum, but it can be readily distinguished by its broad and 

 arcuate canal, and the more elevated and scalariform spire. The swell- 

 ing along the base of the body-whorl in F. maximus also helps to 

 identify the species. 



