674 NEW YORK STATE MUSEUM 



p a t u 1 u s. As the form of the thecae does not permit a reference to either of 

 the two last named species, the one having broader and shorter, the othrr more 

 inclined and curved thecae, it has been with us a (question of either creating 

 a new specific term or extending the definition of D. u i t i d u s sufliciently to 

 include these forms. We have preferred the latter, as the two are connected 

 by such easy gradations that it would be impossible shai'ply to divide them, 

 As, however, in other localities the species is evidently restricted to its typical 

 expression, the fact of the variation calls for recognition, and ^ve propose to 

 designate these larger forms with somewhat less closely arranged thecae as the 

 variety D. nitidus var. g r a n d i s. 



Didymograptus patulus Hall sp. 



Plate 13, figures 8, 9; plate 14, figure 7 



Graptolithus patulnsHall. Geol. Sur. Can. Re p't for 1857. 1858. p.131 

 Graptolithus patulus Hall. Canadian Organic Remains, decade 2. 1865. 



p.71, pl.l, fig.10-15 

 Non Didymograptus patulus Nicholson. Qiiar. Jour. Geol. Soc. 1868, 



24:135 

 Non Didymograptus patulus Nicholson {pars). Ann. and Mag. Nat. Hist. 



ser.4. 1870. 5:340, pl.7, fig.la 

 Didymograptus patulus Hopkinson. Quar. Jour. Geol. Soc. 1875. 31:644, 



pl.33, fig.4a-e 

 Didymograptus patulus Linnarsson. Sver. Geol. Und. Af h. och Upps. 1879. 



ser.C, no.31, p.5 

 Didymograptus p a t u 1 u s Brogger. Die sil. Etagen 2 and 3. 1882. p.39 

 Didymograptus p a t u 1 u s Herrmann (^ars). Geol. Mag. Dec. 3, 1886. 3:14 

 Didymograptus patulus Matthew. Royal Soc. (/an . Proe. and Trans. 1893. 



10:98 

 Didymograptus p a t u 1 u s Matthew. Royal Soc. Can. Proe. and Trans. 1894. 



11:114 

 Didymograptus patulus Gurley. Jour. Geol. 1896. 4:295 

 Non Didymograptus patulus EUes. Quar. Jour. Geol. Soc. 1898. 54:504, 



lig.22, 23 

 Non Didymograptus patulus Tdrnquist. LunJs L'niv. Arsskrift. 1901. Bd37, 



Af.2, Nr5, p.l5, pl.2, %.l-6 



