120 



better specimen than either of them, from the coast of South Caro- 

 lina. It is readily distinguished from the two other species which 

 inhabit our shores, the dathrus of authors, and the lineata, nobis, 

 by the numerous small indented^ lines that occur in the spaces be- 

 tween the costoo, and at right angles with them. 



Infundibultjm depressum. — Shell depressed, fragile, with 

 small concentric irregular wrinkles ; volutions three ; suture not 

 profoundly indented : apex not central ; base oval, almost orbicu- 

 lar ; umbilicus oblong ; internal plate small. 



Greatest diameter of the base rather more than one-fifth of an 

 inch. 



This highly interesting shell was found by Mr. Stephen Elliott, 

 on the coast of South Carolina. Amongst a number of curious 

 shells, natives of New Holland, Timor, and the Isle of France, pre- 

 sented to the Academy by Mr. Lesueur, a species of this genus 

 occurs, which is somewhat similar to ours, but it is much larger ; 

 its greatest basal diameter being three-fourths of an inch in length, 

 its suture is more profoundly indented, and its surface wrinkled 

 with much regularity. 



Natica triseriata. — Shell longitudinally suboval, approach- 

 ing subglobular ; volutions five ; body whorl with three revolving 

 series of large oblique, parallel, oblong-quadrate, dark reddish- 

 brown or blackish spots, about twelve in each series ; umbilicus 

 rounded, not contracted by the callus ; suture not impreseed ; spire 

 with but one series of spots on each volution. 



Length two-thirds ; width eleven-twentieths of an inch. In- 

 habits the Northern coast. Boston harbor. 



This shell may be compared to the JST. intrvcata of Donovan, 

 which is comprehended by Dillwyn amongst the varieties of N. 

 canrena. It certainly appears to be closely allied to that very 

 common species of the British coast in its configuration, excepting 

 that it is perhaps somewhat more elongated, and that the shoulders 

 of the whorls are much less convex, and the suture, consequently, 

 less deeply impressed. In a very perfect specimen presented to 

 the Academy by the Vice-President, Mr. Zaccheus Collins, the 

 two lower series of spots are jointly included by a pale yellowish- 

 brown band ; beneath this band the base of the shell is pure 

 white ) the shell is also white above this band, excepting that the 

 spots of the superior series are connected by a pale yellowish-brown 



