CARBONIFEROUS BRACHIOPODA. 
269 
the lower or attached valve was so likewise. Mr. John Young is, however, of a contrary 
opinion with respect to C. quadrata, and assures me that, after repeated examinations, he 
could detect no perforations in that valve. He has experimented on a number of speci- 
mens, and neither Dr. Young nor himself could detect any punctures even under a high 
magnifying power. This subject will demand further investigation, and a careful exami- 
nation of the attached valves of other species of the genus is much required. 
Genus Terebratula, Llhwyd. 
8. Terebeatula sacculus, Martifi. Dav., Garb. Mon., pp. 14, 213, Pis. I and XLIX. 
I have nothing to alter of what I stated at p. 213 of my Monograph with respect to 
Terebratula sacculus, Martin, and its varieties hastata, Gillmgensis, and vesicularis, but 
I must not omit to record that innumerable minute specimens of the variety sacculus, from 
the dimensions of a small dot to one or two lines in length and upwards, have been found 
by Messrs. Neilson, J. Young, R. Craig, and others, to occur in the Lower Limestone 
series at Dockra Quarry, Trearne, and other places in Scotland. Mr. J. F. Walker has 
also obtained from the Carboniferous Limestone of Kildare, in Ireland, an enormous 
example of the var. hastata (Sup., PI. XXX, fig. 17), measuring two inches and three 
quarters in length by two inches in breadth, and one inch and a half in depth. It 
is the largest specimen of the species I have ever seen. 
Family— SPIRIFERIDtE, King. 
The study of the interior of Brachiopoda possessing spirally coiled lamellce for the 
support of the labial appendages has been no easy matter, and has generally depended 
much upon the fortunate chance of finding empty shells in which these appendages were 
naturally preserved, or in difficult and generally unsatisfactory experiments upon the 
hard limestone matrix which usually fills the shells of the Palaeozoic epoch. It some- 
times happens that the shell was empty, and that the spirals were slightly or thickly 
coated with crystallised carbonate of lime or spar, as may be seen in PI. V, fig. 34, PI. 
yi, fig. 17, PI. XI, fig. 9, and PI. XVI, fig. 7.' At other times the spire and shell 
1 In the 'Transactions of the Linnean Society of London,' vol. xii, pi. xxviii, fig. 1, was published a 
paper read by James Sowerby in December, 1814, and in which that palaeontologist figures and describes 
the spirals of Sp. striata "as a spiral tube," the lamellae, which he figures as a tube, and which he 
