§ Prof. W. King on Spirifer cuspidatus. 
men, though they are arranged somewhat more regularly. 
Fibres well displayed. 
No. 5.—Six sections: none showing decidedly any perfora- 
tions ; a few faint markings, almost as translucent as the fibres, 
may, I suspect, represent them. The fibres, straight and 
twisting, are very well displayed. 
No. 6.—Specimen presented by Professor Harkness. I have 
prepared twenty sections (some very thin) taken from all parts 
—sides, median fold, and area. They were not so easily rubbed 
down as those from Messrs. Birmingham and Morton’s speci- 
mens. Mostof the sections exhibit the fibres, beautifully trans- 
lucent, running straight out or winding about, and strikingly 
resembling those of the recent Rhynchonella psittacea. Not 
one shows anything that could be pronounced to be a perfora- 
tion; but, as usual, obscure markings are present. The sub- 
shell-layers display, in places, slightly raised oval impressions, 
the same as those seen in Mr. Birmingham’s specimen. 
It is important to observe that every one of the previous 
specimens 1s wndoubtedly furnished, as will be seen hereafter, 
with the canaliferous septum. 
No. 7.—This specimen is small, and appears to be a dwarfed 
individual, judging from the unusual thickness of its valves. 
It is from Millicent, and is the original of fig. 19, pl. 8, of 
Mr. Davidson’s ‘ Carboniferous Brachiopoda.’ Dr. Carpenter, 
who has cut the specimen through its umbonal portion, “ feels” 
himself “ justified in confidently asserting that it is essen- 
tially imperforate.” He has given a representation of a 
“transverse section”? of its umbone to show that the “ dental 
laminge are unconnected by any transverse septum, and that 
there is no vestige whatever of the canal’’*. On the latter 
point some considerations favouring a different view will here- 
after be produced. Mr. Davidson has, in the most liberal 
manner, presented me with the two halves, left after Dr. Car- 
penter had cut the specimen, to operate upon, as I thought fit, 
for the benefit of science. 
Twelve sections were obtained, all hard and imperforate, like 
those of the last specimen. Indeed the sections from both are 
perfectly identical, not only in the absence of perforations, but 
in the distinctness, disposition, and translucency of the fibres. 
That this specimen “exhibited not the smallest trace of 
perforations” to Dr. Carpenter is quite admissible. It is ne- 
cessary, however, to state that one of my sections shows a few 
scattered spots, which approach to some of the obscure mark- 
ings noted as occurring in the precited sections of perforated 
* Ann, & Mag. Nat. Hist. July 1867, p. 72, fig. 4. 
