®'* i;(»YAL SOriKTY OF CANADA 



C'oiiDAiTKs NKwuKuaYiK (Dn.) Knowlton. 

 Fig. 12. 

 mb. :-DawBon. Geol. Surv. Can.. 1871. 14; Knowlton, U. S. Geol. Surv., 1889. 

 iToc. U. S. Nat. Mus., XII., 607. 



Dls.-Hamilton Group , Middle Devonian) of Ohio (Newberry); Carboniferous 

 or Onio (Claypole). 



This species was originally described from nmterial collected by 

 i r. Aewberry, who ],as recorded its occiui-ence in the Huron Shales on 

 Huron Elver in Erie County, and about Delaware and at various places 

 m boathern Uhio.^ In the same yt^ar Prof. Knowlton recorded its 

 occurrence in the Carboniferon. of Ohio as reported by Prof. Claypole.^' 

 1 lie orjn,„,l description by Sir William iJawson is very inadequate/ 

 more especially as the characters are compamtive with those of C 

 Hallu which IS preserved only as an opaque object, and from which, 

 thereloro, a correct diagnosis cannot be obtained. The ll-rures illustrat- 

 ing this species are also inadequate, particularly with reference to the 

 general distribution of the bordered pits and the tangential aspect of 

 the medullary ray,..^ In 1889 Dr. Xewberry undertook a revision of 

 the microscopical ch'aracters, and caJled to ids aid P. H (now J)r ) 

 Dudlej-, who ma<le a very careful diagnosis of the structural characters. 

 Ills agrees m essential points with my own diagnosis, and requires but 

 little li any modification.^ 



In a rachai extent of 17 mm., this species shows no evidence of 

 growth rings. Hr. Dudley says the layers of growth .ixe wide but the 

 limits not conspicuous," Init this seems to us clearly one of those cases 

 m which the rings of growth are so poorly defined as to fall under the 

 designution of obscure or obsolete. The tracheids are conspicuously 

 squarish and somewhat unequal in their two diameters, but the walls 

 are un.iorndy of about the same widtli.^ In a radial ,section the ray cells 

 are seen to be of one kind only, resinous and starch be'ai-ing. The 

 lateral walls bear oval, border ed pits from 2-3 per tracheid, but chiefly 



' Geol. Surv. Can., 1871, 14 ~ ~ ' " 



= Jn'l Cincin. Soc. Nat. Hist, 1889, 48-56. 



" Geol. Surv. Can., 1871, 14. 



' Ihid, PI. I., figs. 7. 8. 9. 



» Jn'l Cincin. Soc. Nat. Hist., 1899, 54-55 



" Ihid, 54. 



bul siight " " ' ""*'"''' '" '""^^ "'^^ ^^^'^ ^'^^ ^^« -'"- - 



