BRACHIOPODA. 
301 
the Upper Coal Measures of Madison county, Iowa, where it is said to be 
associated with the Terebratula millipunctata, Hall {—Dielasma bovidens, Martin). 
The original figures showing the outline of the exterior are here reproduced. 
Of the internal structure the authors say that “ the loop seems to be essen¬ 
tially like that of Waldheim:a in 
form, but the crura of the loop ap¬ 
pear to be joined, forming with the 
hinge-plate a foramen of moderate 
size; and the loop-band is armed 
with numerous spines which point 
outward towards the shell in all di¬ 
rections.” 
Fig. 225. 
Waldheimial [Crtjptacanthia) compacta, White and St. John. 
A copy of the original figure. 
, (White and St. John.) 
This shell appears to be very rare, and we have had no opportunity of 
examining specimens. Attention, however, may be directed to a somewhat 
similar form of brachidium from the chert beds of the Burlington lime¬ 
stone, at Burlington, Iowa, belonging to a species whose identity is not fully 
established. This structure is represented in the accompanying figure. From 
a well-developed, elevated and tripar¬ 
tite hinge-plate, bearing a slight bi- 
lobed cardinal process at its apex, 
arises a very short brachidium of the 
type of Dielasma or CRANiENA. The 
outer margins of both descending la¬ 
mellae and the short ascending lamellae 
are bordered with numerous short spin- 
ules. Furthermore, there appears to 
be a solid longitudinal band passing 
from the hinge-plate to the posterior 
curve of the ascending lamellae. This 
curious character is not a septum, as the entire apparatus is elevated from 
the bottom of the valve; but it may prove to be wholly casual, and a result of 
an interlocking of the minute quartz crystals with which the brachidium is 
Fig. 226. A fimbriated DiEEASMA-like brachidium from 
the chert of the'Burlington limestone. 
The median dotted lines indicate the position of the longi¬ 
tudinal band described as probably casual in origin. 
The outline of the valve is wholly constructive. 
