rae: ‘Th ie cheeks form spherical triangles. The ocu- 
liferous ‘prominences are close to the second large 
tubercle on the front. The cheeks are, however, 
quite imperfect. The articulations of the back can- 
not be distinguished from those of the tail. In our 
specimen they are all beautifully distinct, and are 
twenty-two in number. The posterior raised rim of 
the buckler seems to form an articulations; its ex- 
tremities on each side are a good deal thickened and 
expanded. The costal arches suddenly curve down- 
wards and backwards, near their middle, so as to di- 
vide.the abdomen and tail into five unequal sections. 
The whole length is nearly three inches. The 
breadth of the buckler nearly two inches. 
This fine large Calymene was accidentally disco- 
vered on the Helderberg mountain, by my friend, 
’ Professor T. R. Beck. One of the loose pieces of 
sandstone rolling over, near his feet, presented him 
_ the fine natural mould, from which he has kindly per- 
mitted our cast to be taken. The animal relic once 
osed in this matrix, must still be near that locali- 
yet remains undiscovered, to reward the en- 
terprise of some more fortunate naturalist. 
One of our models represents the natural mould 
found by Dr. Beck. The other is a cast taken from 
i it and exhibits, more satisfactorily, the various parts 
of the animal. | 
e 
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