224 BRITISH CARBONIFEROUS BRACHIOPODA. 



Spirifera acuta, Martin. Plate LII, figs. 0, 7. 



Conchyliolithus anomites acutus, Martin. Petrificata Derbiensia, pi. 49, figs. 15, 16, 



1809. 



For a long time I felt much puzzled with reference to this shell, and supposed it the 

 young of some other species. My uncertainty has been, however, recently removed by Mr. 

 Burrow's fortunate discovery of a number of specimens of all ages, and exactly agreeing 

 Avith Martin's description and figure : " Valves convex semicircular, marked with deep, 

 longitudinal equal striae ; hinge patulous, straight, but not extending the whole breadth 

 of the shell ; foramen triangular, large ; beak of the perforated valve prominent pointed, 

 incurved ; the other short and obtuse ; margin acutely crenate, and furnished with a large 

 angular sinus, causing a somewhat strong plicature on the surface of the valves; not 

 frequent; small; limestone; Winster and Croom Hill." None of Mr. Burrow's speci- 

 mens exceeded the proportions of Martin's figure, — viz., six lines in length by about 

 nine in breadth, each valve in adult individuals possessing from seventeen to nineteen 

 angular ribs, the central one being at the same time the largest and most elevated of the 

 valves. Mr. Burrow obtained his specimens from the carboniferous limestone in the 

 neighbourhood of Settle, where the shell is not very abundant. 



Spirifera distans Sow. (p. 46). PI. VIII, figs. 1 — 17. 



To this species I would unite Sp. bicarinatus (p. 47, PI. VIII, fig. 18, and PI. LII, 

 fig. 4), which Prof. M'Coy established on a single very imperfect specimen from Cork, in 

 Ireland. This specimen, now in the possession of Mr. J. Wright, of Cork, has quite the 

 appearance assumed by certain examples of Sp. distans, of which it is, in all probability, 

 a synonym. Prof, de Koninck, in his list of the Carboniferous Brachiopoda of Belgium, 

 published in 1859, places M'Coy 's Sp. bicarinatus among the synonyms of his Sp. Roeme- 

 rianus, but this, I fear, is a mistake, for the original specimens of both would not lead 

 me to a similar conclusion. 



Spirifera cuspidata, Martin (p. 44). Plate VIII, figs. 19 — 24; Plate IX, figs. 1, 2. 



Prof, de Koninck, myself, and others, have been led to suppose Martin's Anomites 

 subconicus (p. 48, PL IX, fig. 3) to be a synonym of Sp. cuspidatus. I am, 

 however, doubtful as to this being a correct opinion, from the fact that on perfectly 

 preserved examples of Martin's A. subconica, of which PI. LII, fig. 4, is an illus- 

 tration, the entire surface of the ribs and shell (area excepted) are regularly traversed by 

 continuous equidistant, sharp projecting laminae, exactly similar to those which cover the 



