1863.] DAVIDSON NOVA-SCOTIAN BKACHIOPODA. 171 



Nova-Scotian specimens of the shell under notice are all very small, 

 hone of those that have come under my notice exceeding 4 lines in 

 length by 5 in width ; they exactly resemble some specimens of the 

 same species found in the Carboniferous shales of Capel Rig, East 

 Kilbride, Scotland. 



Sir C. Lyell mentions having found this shell at Windsor, Brook- 

 field, Shubenacadie, and Debert Eiver, in Nova Scotia; and Dr. 

 Dawson adds East River, but that it is nowhere so plentiful as in the 

 shell-conglomerate of Brookfield. 



5. Spirifeka acuticostata, De Koninck. PI. IX. figs. 7, 8. 



Spirifer acuticostatus, De Koninck, Description des Animaux Fos- 

 siles qui se trouvent dans le Terrain Carbonifere de la Belgique, p. 265, 

 pi. 17. fig. 6. 



Shell small and transversely oval ; valves convex and ornamented 

 with from twelve to fourteen small angular ribs. The mesial fold is 

 comparatively wide, flattened, and longitudinally grooved along the 

 middle. The sinus in the ventral valve has a small median angular 

 rib, which commences at about the middle of the valve and extends 

 to the front. Beak small, incurved ; area triangular and of moderate 

 dimensions. Length 4 lines, width 5 lines, depth 3 lines. 



Upon sending a proof of the plate illustrating this paper to Prof, de 

 Koninck, he wrote back that figures 7 and 8 were referable to his Sp. 

 acuticostatus ; and, except in size, they certainly resemble those given 

 by the distinguished Belgian Professor. It must, however, be re- 

 membered that in some specimens of Sp. cristatus, or of its Carboni- 

 ferous representative, Sp.octoplicatus, the mesial fold is flattened along 

 its middle, and even possesses in some cases a shallow groove along 

 its centre, as seen in De Koninck's Sp. acuticostatus. All these modi- 

 fications in British specimens have been described and illustrated at 

 pages 38 and 226 of my Monograph of British Carboniferous Bra- 

 chiopoda. 



This small shell is very abundant in the shell-limestone of Brook- 

 field, Shubenacadie, and in some other localities in Nova Scotia, where 

 it is always associated with JSp. cristatus, of which it may perhaps 

 after all be no more than a modification. 



Camakophokia and Rhynchwella. 



The specimens referable to these genera sent me by Dr. Dawson, 

 as well as those brought to England by Sir C. Lyell, are generally 

 very small, and not in all cases sufficiently complete to warrant a 

 satisfactory determination. I have, however, carefully represented 

 the principal forms. 



6. Camakophoeia ? globulina ?, Phillips. PI. IX. figs. 11, 12. 



Terebratula globulina, Phillips, Encycl. Metr., vol. iv., Article 

 " Geology," pi. 3. fig. 3, 1834. 



Terebratula rliomboidea, Phillips, Geol. Yorksh.vol. ii. p. 222, pi. 12. 

 figs. 18-20, 1836. 



