168 _ SUPPLEMENT TO THE CRAG MOLLUSCA. 
TEREBRATULA GRANDIS," Bimeninen Supplement, Tab. XI, fig. 5 a—g, from the Cor. 
Crag; Supplement, Tab. VIII, fig. 11 a—e, 
from the Red Crag. 
TEREBRATULA GRANDIS, Davidson. Brit. Tert. Brach., p. 16, 1852. 
Length, 5 inches ; breadth, 34 inches ; depth, 2 inches. 
Localities. Cor. Crag, Ramsholt, Sutton, and near Orford. Red Crag, Walton 
Naze, Sutton, and Waldringfield. 
Some years ago specimens of this species were’procured by myself in great abundance 
both at Sudbourn and Ramsholt, in the Coralline Crag, but recently they have become 
somewhat scarce. This is the largest and most noble of the species that I am acquainted 
with, and if I had to give it a name it should be called nobilissima, but unfortunately it 
has too many synonyms. 
It is only within a few years that I have been able fully to display the imternal 
furniture of this species. A specimen in the British Museum presented by myself and 
found at Ramsholt seemed to give fair promise of permitting the removal of the sand 
from the interior, and I was enabled with care to exhibit 2x s¢d the short reflected loop of 
which I have given a figure. All doubt is by this removed respecting its true generic 
position, Prof. King having imagined that it was furnished with an internal apparatus 
much prolonged, like that which he has taken for the type of his genus Waldheima, 
where the loop is extended to more than two thirds the length of the shell, whereas in 
grandis it proves not to exceed one third. Mr. Davidson always imagined it to be a true 
Terebratula, but he had not seen the perfection of the loop. I may further observe that 
grandis possesses a very long spur or crura, and a very little more extension to this would. 
have united the two parts so as to form a ring like that which characterises the genus 
Terebratulina. Whether this be so in the young state I have not been able to see. 
Specimens of grandis have come into my possession that measured nearly five inches 
in length, and fragments have been found which indicate even larger dimensions. ‘The 
difference of size between the fry or infant state and the full-grown shell is so great as to 
be not often observable in any animal. I have found what there is every reason to believe 
is the young (and perfect) state of this species, with its longest diameter not more than the 
twentieth part of an inch, which will give to the full-grown shell an increase of one 
hundredfold at least iz lénear direction, and as in these large shells the young state of 
the longest or perforated valve has entirely disappeared, probably to the extent of one 
third of an inch, my estimate of these differences between the young and old is rather 
1 For generic and specific descriptions see Davidson, ‘ Monograph of the British Tertiary Brachiopoda,’ 
published by the Palzeontographical Society. 
