Prof. W. King on Spirifer cuspidatus. 5 
single puncture”*. And Dr. Carpenter, noticing “the type 
specimen of Prof. Winchell’s Syringothyris,”’ describes the 
perforations in a similar manner. ‘They are not distributed, 
however, with the uniformity which usually prevails in the 
shells of the perforated Brachiopoda; for patches of imper- 
forate shell intervene between portions that are pretty regu- 
larly perforated, and sometimes a fragment large enough to 
fill a great part of the field of view is entirely imperforate ’’t. 
Owing to the great importance which attaches to the per- 
forated character of Spirifer cuspidatus, I have taken upon 
myself the labour of preparing a number of sections, made 
parallel to the surface of the valve, and taken from various 
specimens of this and other species. I shall now proceed to 
detail the result of my examination, which has generally been 
made with object-glasses magnifying from 60 to 120 diameters. 
No. 1.—Specimen from near Tuam, presented to the Geolo- 
gical Museum of Queen’s College, Galway, by Mr. Birming- 
ham, and noticed in my former paperf. 
Six sections, easily rubbed down, were prepared: they show 
the test distinctly formed of long, slender, flattened, sub- 
translucent fibres, running straight or winding about most 
irregularly. Interspersed among the fibres, in most of the 
sections, occur a number of spots, undoubtedly transverse sec- 
tions of tubular perforations, which, varying in size, have in 
general a diameter about equal to the width of two fibres. 
(See fig. 2.) Dr. Rowney§, who has measured the perforations, 
states that, though often smaller, they rarely exceed 7455 inch in 
diameter: they have arude linear or quincuncial arrangement, 
and are from +25 to sy inch apart from one another||. They 
are filled with a granular substance, in some cases quite dark- 
coloured, generally lightish brown, and often very pale; be- 
tween one extreme and the other there are intermediate shades 
* Proc. Acad. Nat. Sc. Philadelphia, Dec. 1865, p. 277. 
+ Ann. & Mag. Nat. Hist. July 1867, p. 71. 
t Geological Magazine, June 1867. . 
§ I must not forget to acknowledge the great assistance my colleague 
has afforded me in my histological researches in connexion with the va- 
rious specimens I have had under examination. 
|| Dr. Carpenter, who has only given the size of the perforations as they 
oceur in “ Professor Winchell’s type specimen,” states that they are 
“ about 1-3000th of an inch in diameter,” and “set at an average distance 
of about 1-300th of an inch from each other.” Compared with the per- 
forations in other Palliobranchs, those of Spirifer cuspidatus are evidently 
very minute. In Aingena lima, a cretaceous species, whose perforations, 
according to Dr. Carpenter, ‘are smaller than those of any Terebratula, 
recent or fossil, their diameter is scarcely 1-2000th of an inch.” (Intro- 
duction to Davidson’s Monograph, p. 28.) 
