STUDY OF THE GRAPTOLITES. 233 



1860. J. Hall, in continuation of the paper from the Twelfth Report 

 on the State Cabinet (from Palcsontology of New-York, Yo\. iii, Supp,), 

 described additional species of Graptolithus, Retiograptus, Thamnograp- 

 tus and Rastrites as above [Thirteenth Report of the State Cabinet, pp. 

 55-64, 1860). 



1861. J. W. Salter, in "New Fossils from the Skiddaw Slates," noticed 

 the occurrence of several species of Graptolithus, and the discovery of a 

 branching form similar to those which Sir William E. Logan first brought 

 to light in Canada, which he proposed to term Dichograptus [Geologist, 

 Vol. i, p. 74). 



1861. Prof. M'CoY sent to the writer a proof of a plate of graptolites 

 from the " PalcBontology of Victoria.^^ Among the figures are species 

 closely resembling or identical with G. ramosus, G. furcatufi, and G. 

 gracilis; while others resemble G. pristis, G. Sagittarius, &c. The de- 

 scriptions or farther illustrations have not come under our notice. 



1861. E. Billings " On the Occurrence of Grraptolites in the Base of 

 the Lower Silurian." The paper^contained a review of the work of Frie- 

 DRICH Schmidt, and a comparison of the graptolitic zones in Europe and 

 America, with a view to show that the graptolite-schists of Norman's Kill 

 near Albany are not in the upper part of the Lower Silurian division, 

 or Hudson-river group [Canadian Naturalist and Geologist, Vol. vi, pp. 

 344 and 348). 



1863. Sir William E. Logan recognized the occurrence of Graptoli- 

 thus bicornis, G. ramosus, G. mucronatus, and G. pristis, characteristic 

 species of the shales of Norman's Kill, in the Utica and Hudson-river 

 formations of Canada [Geology of Canada, p. 200, and Catalogue of Fossils, 

 p. 942. Idem, Graptolites of the Quebec group, pp, 226 and 228). 



1863. J. W. Salter (Note on Skiddaw-slate Fossils) noticed some 

 new species of graptolites, proposing the new genus Tetragraptus, and 

 describing the genus Dichograptiis previously proposed and cited above, 

 including other characters [Quarterly Journal of the Geological Society, 

 Vol. xix, pp. 135-140, with illustrations). 



1866. Henry Alleyne Nicholson, " On some Fossils from the 

 Graptolitic Shales of Dumfriesshire.^^ This paper anounces the discovery 

 of numerous minute bodies in the graptolitic shales, and associated with 

 the G. sedgwickii in such a manner as to sustain the belief that they are 

 ovarian vesicles, or graptolitic gonophores similar to those found in the 

 shales of Norman's Kill, near Albany [Proceedings of the British Asso- 

 ciation, Thirty-sixth meeting, 1866, p. 63). 



1867. William Carruthers, " Graptolites ; their Structure and Syste- 

 matic position,^' with illustrations [Intellectual Observer, Nos. Ixiv and Ixv). 



^*^ The Graptolithus from the Hoosic slate-quarries was named by 

 Prof. Eaton Fucoides secalinus, and the specimens were thus labeled in the 

 Cabinet of the Rensselaer School at Troy, as known to the writer from 

 1832 to 1836 ; but we have been unable to find any published descriptions. 



[Assem. No. 239.J 30 



