HISTORY. 3 



ture by substituting Sandberger's name, G. cancellata, for the G. sowerbyi of 

 doubtful origin, and by restricting G. quadrisulcata to the Carboniferous species, as 

 had already been done by de Verneuil. In the Appendix J to the same work 

 Salter described and figured a new Upper Silurian species, G. subtilis, which is 

 also referred to by M'Coy in the text. In 18G0 Salter 2 described and figured four 

 species, G. laevigata, G. homfrayi, G. margaritif^ra, and C. curium. In 1867 the 

 most important work upon this genus appeared in Barrande's ' Monograph of 

 Palasozoic Pteropods,' ' A in which he described and figured twenty-seven Bohemian 

 species, giving also a general account of the genus, details of structure, and the 

 horizontal and vertical distribution. In 1873 Salter 4 catalogued, without descrip- 

 tion or figures, two new species in the Woodwardian Museum, Cambridge, under 

 the names G. clavus and G. bifasciata. The former, belonging to the Fletcher 

 Collection (reg. no. a. 878) is said to come from the Wenlock Limestone near 

 Dudley, and was described and figured by Cowper Reed 5 in 1902. As, however, 

 both in character and preservation, the fossil is identical with small specimens of 

 C. quadrisulcata from the ironstone nodules of the Coal Measures, and is totally 

 unlike any fossil I have seen from the Wenlock Limestone, I am of opinion that 

 a wrong horizon has led to the institution of a false species, which must therefore 

 be abandoned. With regard to G. bifasciata, also described and figured by Cowper 

 Reed, 5 the species was unrecognisable from Salter's note, and the same form in 

 Sweden was described and figured eleven years later by Lindstrom/' under 

 the name G. aspersa; Lindstrom's name, and not Salter's, should therefore be 

 adopted for the species. Another new species was added to the list in 1875 by 

 Hicks, 7 who described and figured a somewhat doubtful form from the Lower 

 Ordovician of South Wales under the name G. llanvimensis. Three years later 

 we find a reference by Etheridge 8 to some fragments of a new species from the 

 Lower Carboniferous of Scotland, and these fragments undoubtedly belong to the 

 new species, G. tenuis, described subsequently. In 1884, in the important mono- 

 graph to which reference has already been made, Lindstrom described and figured 

 five species from Gotland, and in 1893 Holm 9 completed the description of the 

 Swedish members of the family. In addition to the description of nine new 



1 Loc. cit., Appendix A, p. vi, and p. 287, pi. I.L, fig. 24. 



2 J. W. Salter in Ramsay's ' Geol. North Wales,' Mem. Geol. Surv., vol. iii, ed. 1 (1866), pp. 354, 

 355; ed. 2 (1881), pp. 562, 563, pis. x, xiA. 



13 J. Barrande, ' Syst. Silur. du Centre de la Boheme ' (1867), vol. iii. 



* J. W. Salter, ' Catal. Cambr. and Silur. Foss. Geol. Mus. Cambr.' (1873), pp. 153, 171. 



3 F. E. C. Reed, ' Geol. Mag.' [4], vol. ix (1902), p. 123. 



G. Lindstrom, " Silur. Gastr. and Pterop. Gotland," ' K. Svenska Vet.-Akad. Handl.,' vol. xix, 

 no. 6 (1884), pp. 39 — 47, pis. i, vii, xix. 



7 H. Hicks, ' Quart. Journ. Geol. Soc.,' vol. xxxi (1875), p. 189, pi. xi, figs. 5, 6. 



8 R. Etheridge, jun., 'Quart. Journ. Geol. So^.,' vol. xxxiv (1878), p. 19. 



9 G. Holm, " Hyolithidie och Conulariidse," ' Sver. Geol. Undersok.' (1893), ser. C, no. 112. 



