1898.] NATURAL SCIENCES OF PHILADELPHIA. 415 



1st. — A point on the main canal in North Carolina, two to three 

 miles south of the Virginia boundary. 



2d. — A point on the main canal in Virginia, about five miles 

 north of the feeder, or four miles north of Wallaceton, a small Post 

 Office and settlement on drained land near the centre of the swamp. 



3d. — A point about midway of the feeder, say one and one-half 

 miles west of its junction with the main canal. 



A noticeable peculiarity, as stated by M. Homer, is that the 

 collections from the main canal, from both the Virginia and North 

 Carolina localities, contain great numbers of the large conch, Fulgur 

 carica, while this shell is wanting in those thrown out from the 

 feeder. Here, however, the oysters, Ostrea virginiea, are exceed- 

 ingly numerous, and many of them are of extra large size, one speci- 

 men in the possession of M. Homer measuring ten inches in length 

 and four and one-half inches in width. 



But few specimens, comprising only three species, were brought 

 from the locality south of the Virginia-North Carolina line. M. 

 Homer, however, states that the shells seemed as varied in form and 

 as plentiful there as north of Wallaceton. 



In one lump of clay matrix, about the size of a walnut, obtained 

 from the bottom of the dredgings north of Wallaceton, we discov- 

 ered, on a preliminary microscopic examination, a very few diatoms, 

 and a few, though perhaps a slightly larger number of sponge spicu- 

 les. A separation and cleaning of the diatoms from this lump of 

 clay was made by a fellow member of the Academy, John A. 

 Shulze, after which the forms were identified by another member, 

 Prof. C. S. Boyer. The mollusks were jointly identified by Prof. H. 

 A. Pilsbry of the Conchological Section of the Academy and C. W. 

 Johnston, Curator of the Wagner Free Institute of Science. 



Below we tabulate the mollusks according to their range in geo- 

 logical time into three columns headed Miocene (M), Pliocene (P) 

 and Recent (R) — under Recent are included both Pleistocene and 

 now living forms. On the right, in two additional columns, we note 

 the occurrence of such of the forms as have been found in the Croa- 

 tan, N. C, and the Waccamaw, S. C, beds, both of which contain 

 a somewhat similar molluscan fauna. 



The geological range, as noted in the first three columns, we take 

 from Dr. W. H. Dall's " Tables of Species " from the Waccamaw 

 and the Croatan beds. 1 



1 Transactions of the Wagner Free Institute of Science, Vol. Ill, Part 2, 

 pages 210 to 215. 



