298 Scientific Intelligence. 
chenide, a Family of Acephalous Mollusca,” (33-62), “ On the Classifi- 
cation and Synonymy of the recent species of Pholadide,” (63-93), “Notes 
on American fresh water Shells,” (95-96), “Monograph of the Lies 
Teredonide,” (97-126), and “Description of a new Genus and Species 
- Pholadide,” (126-127). 
The Pholadacea, as will be seen from the above list, are divided into 
three families, first severally distinguished by Mr. Carpenter. These fami- 
ies may be natural, the Teredonide being most justly separated from the 
Pholadide, with which they had been confounded until distinguished 
by Carpenter; but, to the number admitted by Mr. Tryon, would per- 
haps be properly added another, the Aspergillide of Gray ; the presence 
of fringes or tentacles at the front of the mantle, and ‘the consequent 
development of tubuli radiating from the edge of the anterior disk of 
the tube, conjoined with the modification of the other part, appear fully 
to justify that distinction. There would then be four allied families, 
Pholadide, Teredonide, Gastrochenide and Aspergillide or Brechitid . 
The propriety of the erection of this group of families into an “ order, 
s has been proposed by some and adopted by Tryon, is extremely 
questionable. 
The genera of the Pholadacea accepted by Mr. Tryon are numerous, 
but apparently not more so than are natural. A number, it is true, have 
en 
The “ description of a new genus and species of Pholadide” forms a0 
Appendix to the monograph, and makes known an — addition 
n, fro w York Bay; 
monograph is exhaustive, almost every reference to any genus eine 
cies having been given. The author proposes to publish an illustrate? 
descriptive monograph of the same Pholadacea at a future time, 
nished with requisite material—for which he appeals to collectors. of 
_ In the “Notes on American fresh water Shells,” the subdivision © 
the genus Vivipara Montfort (properly Viviparus), into four sabgenee 
_Vivipara, Tulotoma Hald., Melantho Bowd, and Haldemania Tryo”, 
proposed. This view will doubtless be accepted, although the ert 
guishing characters of Melantho are not given e latter includes 
ordinary Paludine of the Eastern States, and is distinguished by 
form of the shell, the sigmoidally sinuous outer lip, &e. A family pt 
nicolide is also proposed for the reception of Amnicola, but is unacce 
panied by a diagnosis. The distinction of that genus from the pert 
ride as well as Littorinide and Rissoida, is justifiable; it is indeed m 
nearly related to the Melanians but has no lateral jaws. The chi 
