BRACHIOPODA. 
Shell punctate; spheroidal; beaked; hinge line shorter than 
the width of the shell; cardinal extremities rounded. Internal 
Spires as in Spirifera. Ventral valve with a flattened space or 
false area beneath the beak, on each side of which, at the base, 
is a strong tooth; a narrow medio-longitudinal septum extends 
from the beak to the base. Dorsal valve furnished with a strong 
spatulate cardinal process, which, rising vertically from the 
cardinal margin, is closely grasped at its base by the cardinal 
teeth of the other valve; and thence bending abruptly upwards, 
and expanding, is projected into the cavity of the opposite beak, 
lying close upon the under side of the false area. Cardinal pro- 
cess grooved to allow of the passage of the peduncle, for the 
protrusion of which a minute foramen is sometimes observed in 
the beak. The crural processes originate at the base of the 
cardinal process. A medio-longitudinal septum as in the ventral 
valve. 
Surface of shell apparently smooth, under a lens punctate ; 
when perfect, covered with minute hair-like spines. 
The larger species of this genus present some analogy in 
external appearance with Spirigera, and the presence of internal 
spires increases the similarity. The cardinal teeth resemble those 
of Spirigera and Merista. In form, and in the punctated test, it 
simulates Magas; while the elongate cardinal process of the 
dorsal valve resembles that structure in Thecidium. 
Distribution, 7 species. Silurian. United States, England 
TREMATOSPIRA, Hall, 1859. 
Hiymology, trema, a foramen, and spira. 
Example, T. multistriata, Hall. 
Shell transverse, elliptical, or subrhomboidal, furnished with 
internal spires (arranged as in Spirifera); hinge line shorter 
than the width of the shell. Valves articulated by teeth and 
sockets ; beak of ventral valve produced or incuryed and trun- 
cated by a small round perforation separated from the hinge 
line by a deltidium. A deep triangular pit or foramen beneath 
the beak, which is filled by the closely incurved beak of the dorsal 
valve. False area sometimes defined. 
Distribution, 7 species. Upper Silurian—Middle Devonian. 
United States. 
This genus and the next appear to be closely related te 
fielzia. 
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