52 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
Generic and Specific Descriptions. 
Genus Camarophorella Hall and Clarke (emended).' 
1894. Camarophorella Hall and Clarke, Thirteenth ann. rept. state geol. 
[of New York], p. 838. 
1895. Camarophorella Hall and Clarke, Geol. surv. New York, palaeon- 
tology, vol. 8, pt. 2, p. 215. 
Shell transversely elliptical to elongate-elliptical or ovate; broadest 
near the micklle or above or below it; both valves about eqtially con- 
vex; beak of pedicle valve moderately incurved, not enclosing that 
of brachial valve; pedicle opening moderately large, terminal. Fold 
and sinus present or absent, never showing more than a moderate 
development. 
Pedicle valve with a spondylium formed by the coalescence ventrally 
of the dental lamellae, and supported throughout most or, usually, 
all of its length by a median septum which is slightly longer than the 
spondylium and about half as long as the valve; all muscles of the 
pedicle and all of the ventral attachments inserted on this platform; 
edges of the spondylium thickened and set into deep sockets in the 
brachial valve on either side of the hinge plate. 
Brachial valve with a high, triangular, median septum extending 
one half the length of the valve and supporting posteriorly a strong, 
deeply concave hinge plate; a platform takes its origin beneath the 
hinge plate and extends the length of the septum, being penetrated 
by and attached to it. On either side of this septum the platform is 
bent toward the valve and attached to its inner surface, forming a 
cavity between it and the valve. To it were attached the adductor 
1 Comparison of the emended with the original description will reveal an apparent 
contradiction in the description of the spondylium. This is due to the lax usage of the 
term spondylium by Hall and Clarke, although they proposed to restrict it definitely 
to the muscular platform of the pedicle valve (Hall and Clarke, '95, p. 332). Under 
Camarophoria the authors describe "in the pedicle-valve. . . .a moderately large spondy- 
lium which, in the umbonal region, rests upon the bottom of the valve, but anteriorly is 
supported by a median septum" (p. 212). On the following page reference is made to 
"the brachial spondylium of Camarophorella." Thus, two structures, one in each valve, 
are called by the same name in reference to such a structure: "At the same time its 
internal characters are normal for Camarophoria, except that the broad, spatuliform 
spondylium rests upon the valve for most of its length, the median septum penetrating it 
and projecting above it into the interior cavity of the shell." There is nothing to in- 
dicate which valve is here referred to but doubtless it is the brachial platform which is 
described. In the present paper the term spondylium is limited to the structure 
occurring in the pedicle valve. 
