No. 1596. DALMANELLAS OF THE CHEMUNG— WILLIAMS. 49 
The hinge teeth sharply differentiate the muscular scars from the 
sides of the shell; the muscular scars run up to a blunt point in the 
pedicle area, and are bilobed anteriorly. A slight, rim-like elevation 
generally continues from the base of the teeth around and in front 
of the muscular scars. 
In the brachial valves the muscular scars are generally only faintly 
indicated, though in specimens with thick shell they are distinguish- 
able as four subquadrate scars occupying the deepest portion of the 
valve (in molds of the interior they show on the highest part of the 
surface), the posterior edges and the interior edges of the. posterior 
set are most strongly differentiated from the general surface by the 
median ridge extending forward from the base of the cardinal 
process. . 
‘The crura are small at their bases, and in size inferior to the base 
of the cardinal process which rises abruptly from the general shell 
wall, and is pointed strongly backward. ‘The space back of the mus- 
cular sears in the brachial valve is about one-tenth of the total length 
of the shell. It is twice as large in shells of D. danbyi of the same 
SIZe. 
In a set of specimens preserving the shell, from locality 517 A7,¢ 
the lines are beautifully rounded above and separated by flat- 
tened spaces (1. e., striae) shehtly broader than the lines. This ap- 
pears to be a character distinguishing this species from 2. danbyZ, in 
which the lines are subangular. 
The following specimens, representing the characteristics of the 
species as above restricted, are figured on Plate II. 
Fig. 13 (1225 B1, specimen No. 21), mold of interior of brachial 
valve. 
Fig. 24 (1225 B1, specimen No. 37), mold of interior of pedicle 
valve. 
*'The numbers and letters associated with the specimens cited in this report 
are locality numbers of specimens listed for the U. 8S. National Museum. When 
numbers are given they are serial numbers assigned to the collections of the 
Devonian made by the author and his party for the U. S. Geological Survey. 
Example 517 Westville, Chatauqua County, New York; 1225=Villenova, 
Chautauqua County, New York. In the case where the label begins with let- 
ters, the letters indicate the quadrangle, the number and letter following indi- 
cate the block of the 15-minute quadrangle. As for instance Ith. 3 K, means 
Ithaca 15’’ quadrangle, third block of the one-minute blocks from left to right, 
and block K of the one-minute blocks from top of quadrangle down lettered 
alphabetically, or the eleventh in order. 
The letters and numbers following these primary marks indicate the section 
number and the zone of the section according to the system used in gathering 
and labeling the specimens. The specimens of Dalmanellas have been perma- 
nently mounted on tablets. In case several Dalmanellas are mounted on ae 
Single tablet serial numbers are assigned the specimens. These are indicated 
by the specimen numbers. 
IPIROG, IN, WE Wolly Soodhy— 0 
