FEO:\r XOllTII AMERICA, WALES, AND IRELAXD. 5 



4. L. Claijpolei, sp. nov. PI. III. fig. 17. Lower Silurian. 



Cincinnati, 

 ^ &. Q. L. aha (Conrad) et L. Jonesi, Hall. (L. alta, var., 



PL T. %. 6.) Upper Siluriau. New- York State. 

 7. Leperdiiia nana?, Jones, PL IV. fig. 4. Lower Silurian. 



Wales. 

 XL Xestoleberis. Lower and Upper Silurian, Carboniferous, and 

 Ilecent. 

 1. X lVri<jJitii, sp. nov. PI. IV. figs. 14, 15. Lower Silurian. 



Ireland. 



I. Genus Primitia, Jones and HoU, 1865. 

 Frimitia, J. & 11. 'Ann. & Mag. Nat. Hist.' ser. 3, vol. xvi. p. 415. 



1. Primitia mundula, Jones, var. cambrica, nov. (PI. IV. fig. 7.) 

 Size : length "86 mm., height "5 mm. 



This is a true Frimitia, related to F. mundida, Jones, especially 

 fig. 31, pi. vi. 'A. M. X. H.' ser. 2, vol. xvi. 1855, although the 

 valve is not quite so regular in outline, and the sides of the sulcus 

 are not so stifiiy tuberclcd. We may call it var. cambrica. 



From the I5ala beds, near Welshpool, Montgomeryshire *. 



Frimitia miuidida, with its varieties, is a very wide-spread species. 



2. Primitia humilis, Jones & Holl ; var. humilior, nov. (PI. IV\ 



fig. 5.) 



Size : length -86 mm., height -5 ram. 



Fig, 5 is a simple suboblong Frimiia, of the same type as F. 

 humilis, J. & H., 'Ann. & Mag. Xat. Hist.' ser. 5, vol. xvii. 1886, 

 p. 409, pi. xiv. figs. 6 »t 9, but is longer, higher behind, and has a 

 mucli fainter sulcus. 



From the Bala beds near Welshpool. 



3. Pri3iitia seminulum, Jones. (PL II. fig. 2.) 



Frimitia sem'mdum, Jones, 'Ann. & Mag. Nat. Hist.' ser. 5, 

 vol. xvii. 1886, p. 413, pi. xiv. fig. 14. 



Size : fig. 2, length 1-2 mm., height "8 ram. 



Fig. 2 is a characteristic specimen, but the valve is broken away 

 below and behind the centre. The meshes of the ornament are spe- 

 cialized at the sulcus. 



Ill a limestone consisting of Crinoidal joints, Brachiopods, &:c., 

 belonging to the Hamilton Group, from Eighteen-mile Creek, Lake 

 Erie Shore, N. Y. 



F. seminidum is known in the Upper Silurian of Wales, Shrop- 

 shire, and Scandinavia. 



4. Primitia Morgant, sp. nov. (PI. IV. figs, da, b.) 

 Size : lengtli -5 mm., height '3 ram. 



A small, semicircular, bituberculate, punctate Frimitia (the in- 



* Figs. 4-13 of PI IV. were sent to me by Mr. J. Bickertou Morgan, F.G.S., 

 of Welshpool, by whom they were collected from dark shales of Bala ago 

 at Gweruybrain, near Welshpool, Moutgomeryshire, North Wales. 



