128 Aug. F. Foerste 
Dalmanella emacerata, Hall 2 =^ 
{Plate VIII, Figs. 3 A, B) 
Dalmanella emacerata was described by Hall in the Thirteenth 
Report of the Regents of the University of New York, State Cabinet 
of Natural History, page 121, in 1860, and first figured in the 
teenth Report of the same series, in 1862, by Figs. 1 to 3, on plate 
11 . 
In the original description the shell is stated to be ^^semi- 
elliptical, length and width about as five to seven; hinge-line 
nearly equalling the width of the shell. 
Fig. 1, on plate II, of the Fifteenth Report, represents a brachial 
valve 15 mm. in length and 20.5 mm. in width; the ratio of length 
to width being as three to four. Fig. 2 on the same plate represents 
a pedicel valve almost 14 mm. in length and 21 mm. in width, 
the ratio being as two to three. 
The type specimens of Dalmanella emacerata, numbered 1339-2, 
are preserved in the American Museum of Natural History in 
New York City. Both are brachial valves. The one regarded 
as serving as a basis for Fig. 1 in the Fifteenth Report, is 14.5 mm. 
in length, and 20.8 mm. in width. The dimensions, therefore, 
agree very well with the ratio of five to seven, and the outline is 
sufficiently near that presented by Fig. 1 to have served as a 
basis of this figure. 
The chief difference betw^een the specimens typified by Figs. 
1 and 2 of the Fifteenth Report lies in the more quadrate outline 
of that typified by Fig. 1, and the more elliptical outline of that 
represented by Fig. 2. Specimens of the first type are figured in 
the Bulletin of Denison University, vol. XIV, page 213, and plate 
IV, Fig. 1, as Dalmanella emacerata-filosa. They evidently rep- 
resent typical forms of Dalmanella emacerata, and the varietal 
name filosa should be dropped. Specimens of the second type 
are represented by Fig. 5 on plate VII of the same volume, page 
322, as Dalmanella hrevicula. 
In typical Dalmanella emacerata, there is a tendency toward the 
greatest width lying near the line across the middle of the shell. 
In typical Dalmanella emacerata-brevicula, the greatest width of 
the shell lies distinctly posterior to a line across the middle of 
Thirteenth Regents Report, Univ. of New York, p. 121, 1860. 
