BRACHIOPODA. 753 
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The cardinal; process is a low, transverse, sessileapophysis, 
having its surface vertically"striated ; occasionally itzis bipartite 
or it may be wholly resorbed. 
The crura are long, straight and slightly divergent; their 
union with the primary lamelle> of the spiral ribbon is at 
a broadly obtuse angle. The brachial coils are directed 
outward and upward toward the cardinal angles of the valves, 
and their variation in size and direction is in keeping with the 
differences in the marginal outline of the shell. The number 
of volutions of the ribbon exceeds that in any other genus of 
brachiopods. There is no jugum; its position, however, is indi- 
cated by a pair of short spinous processes originating on the 
primary lamella soon after their junction with the crura, and 
which are directed inward with a slight convergence. 
The muscular area has about the same extent as that of the 
pedicle-valve, though less distinctly impressed and generally more 
elongated. It is constituted of two pairs of adductor impressions 
with their surfaces radiately or palmately striated. The anterior 
pair are central, narrow at their posterior extremities which are 
embraced by the broader posterior scars. 
A faint median septum is sometimes present. In some 
instances of importance the socket walls are supported by septa 
which may be considerably produced over the bottom of the 
valve. 
In both valves the genital region is distinctly punctated, but 
vascular markings are rarely observed. 
Type, Anomites striatus, Martin (1809). Carboniferous lime- 
stone. 
This comprehensive genus has been divided into the following 
sections, based largely upon American species, though it is 
believed that with the addition of some equivalent division 
the grouping will be found generally applicable to all Spirifers. 
Section I. Rapratt. (Plate 23, figs. 1-15.) Typical example, 
Spirifer radiatus, Sowerby (including S. plicatellus, Sowerby). 
Smooth, radially undulated or plicated ; fold and sinus smooth ; 
entire surface covered with fine, filiform, radiating strie, which 
may be minutely crenulated or granulose. 
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