Prof. W. King on Spirifer cuspidatus. 5 



single puncture"*. And Dr. Carpenter, noticing " the type 

 specimen of Prof. Winchell's SyringothyriSj'' 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 "f* 

 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 

 vmade 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 paper f. 



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. Bowney §, who has measured the perforations, 

 states that, though often smaller, they rarely exceed toVo i^^ch in 

 diameter : they have a rude linear or quincuncial arrangement, 

 and are from y^ to -^^ 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. I860, p. 277. 



t Ann. & Mag. Nat. Hist. July 1867, p. 71. 



X Geological Magazine, June 1867. 



§ I must not forget to acknowledge the great assistance my colleague 

 has afforded me in m}- histological researches in connexion with the va- 

 rious specimens I have had under examination. 



II Dr. Carpenter, who has only given the size of the perforations as they 

 occur in "Professor Winchell s type specimen," states that they are 

 " about l-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 Kingena lima, a cretaceous species, whose perforations, 

 according to Dr. Cai-penter, '' are smaller than those of any Terebratuln, 

 recent or fossil, their diameter is scarcely l-2000th of an mch." (Intro- 

 duction to Davidson's Monograph, p. 2S.) ' ■ > 



