BRACHIOPODA. 
279 
processes of other Terebratulas. From the upper part of these rods arises the 
brachial support, consisting of a very slender calc-ribbon, which, somewhat as 
in Waldheimia, first extends to the vicinity of the anterior margin, then bends 
abruptly backward, inclining somewhat toward the center of the shell-cavity, 
and is closed by a short, straight cross-piece, above which the ascending branches 
project as short points; this cross-piece and the upper part of the ascending 
branches lie below the plane of the straight rods. While in the small valve 
the hinge-muscle and the inner pair of dorsal pedicle-muscles are attached to 
the callous process, the outer pair of pedicle-muscles appears to have been 
fastened to the upper portion of the crura. The impressions of the adductors, 
of which but two are discernible, lie somewhat above the middle of the valve, 
in two cavities, often very deep, semicircular on their posterior margins, but 
oblique and shallow in front. 
Fig. 201. Fig. 202 . 
' Megalanteris Arcliiaci, tie Verneuil. 
Fig. 201. An internal cast of the umbonal region of the pedicle-valve. (Suess.) 
Fig. 202. The interior of the umbonal region of the brachial valve; showing the cardinal process. (De Veeneuil.) 
“ In the large valve the muscular area is close about the umbo, and is similar 
to that of the terebratuloids; a middle elongate space corresponds probably to 
the adductor muscles; on either side of this, one recognizes the impressions of 
the diductor muscles, and outside and somewhat behind these, though not 
always clearly defined, are the areas of insertion of the ventral branches of the 
pedicle-muscle, which also seems to lie on the inner surface of the dental 
plates. 
“ On the inner surface of both valves may be distinguished four impressions 
of trunk-sinuses, from which arise no dichotomous branches as in other tere¬ 
bratuloids. The posterior part of the outer pair of these sinuses is in each 
valve surrounded by the impressions of the genital organs, whose outer portion 
