Prof. W. King on Spirifer cuspidatus. 21 
pressions there is situated a smaller pair, neither well marked 
nor distinctly defined, 6,6; and the rather prominent ridge, 
c, immediately behind the latter, I suspect represents another 
air. 
: Besides the preceding, other muscular impressions are indi- 
cated by the longitudinal lines on and near the cast of the 
canal (fig. 32 a) belonging to the transverse septum*. These 
markings are important as clearly showing that the canal 
served as a muscular support, though such an office must have 
been limited to its open or terminal portion. The canal, from 
what has been adduced in the previous section, bears evidence 
of its older portion having become gradually closed up by the 
deposition of shelly matter in its interior. 
It is not altogether safe to identify the different muscles 
which belonged to Spirifer cuspidatus with those known to 
characterize certain recent Palliobranchs, as made known by 
various writers, including myselft. I may, however, be 
allowed to offer a few suggestions in this direction. 
The impressions lettered a, I have little doubt, represent the 
ventral pedicle-muscles; those marked 6 may, I am led to 
suspect, have been produced by the valvulars (‘‘ adductors”’) ; 
and those distinguished by the letter ¢ are probably the repre- 
sentatives of the cardinals. 
There is some difficulty with the muscles belonging to the 
canal; and this is increased by the uncertainty that attaches to 
* A representation of the canaliferous septum, as indicated by the cast 
of it, is given in fig. 33. 
+ The description which I have published, illustrating the muscular 
system of Waldheimia australis, first appeared in the ‘Ann. & Mag. Nat. 
Hist.’ vol. xviii., July 1846, and was copied, with the addition of some 
figures, in my ‘ Monograph of Permian Fossils,’ pp. 73-76 (1850). It was 
the first one in English giving an account of a pair of muscles which pass 
from the inner surface of the perforated valve to the process (cardinal) 
in the centre of the hinge of the opposite valve. But it came to light 
some years afterwards (see Gratiolet, Académie des Sciences, Paris, 
July 11, 1853; and Davidson, Annals & Mag. Nat. Hist. ser. 2. vol. xvi. 
December 1855) that I had been anticipated by Prof. Quenstedt, who, in 
1835 (Wiegmann’s Archiv, vol. xi. pp. 220-222), pointed out the occur- 
rence of the same muscles in Rhynchonella psittacea. Myr. Davidson, who 
has taken much pains in elucidating the history of the discovery of this 
point, and making known the general myology of the Palliobranchs (see 
Introduction to ‘Monograph of British Fossil Brachiopoda,’ pp. 53-56 ; 
and ‘Annals,’ above cited), has faithfully credited the various writers who 
have treated of the subject with the merits to which they are individually 
entitled. With the exception of some discoveries explaining the mode of 
attachment of the pedicle (or, rather, its capsule) to the surface of the 
umbonal cavity, and proving the existence of certain accessory muscles in 
the same part, nothing of importance in palliobranchial myology has been 
made known since the original publication of my description. 
