LIST OF ILLUSTRATIONS. 



PLATES. 



Kacins 

 pao:e. 



Plate 1. — Figs. 1. 2, Dencli*ograi)tns? problematicus Spencer; 3, Dendro- 



graptiis raniosus Spencer; 4, Denclrograptus ontarioensis, 



new species 06 



2. — Fig. 1, Acauthograptus granti Spencer ; 2. Dendrograptus 

 pliainotheca. new species: 3, Dendrograptus praegracilis 

 Spencer; 4, Dictyonema tenellum Spencer; 5, luocaulis? 

 thallosus, new species; (>. Inocaulis? s'trictus, new species BS 



3. — Fig. 1, Dictyonema crassibasale, new species; 2, Dictyonema 

 stenactinotuui, new species; 3, Callograptiis strictus, new 

 species ; 4, Acanthograi)tus granti Spencer ; 5. Acantho- 

 graptns cliaetopliorns, new species 70 



4. — Fig. 1, Dictyonema spenceri, new species; 2, Dictyonema pa- 

 rallelum, new species ; 3, Dictyonema desmoides, new species ; 

 4. Dictyonema polymorplinm Gurley ; 5, Acanthograptus 

 pulclier Spencer 72 



5. — Fig. 1, Inocaulis vegetabilis, new si)ecies; 2. Inocanlis diffusus 



crassiramus, new variety 74 



TEXT FIGURES. 



rag;(». 



Figs. 1-7. — 1, DendrograiJtus dawsoni Spencer— a frond, natural size, 

 and a branch enlarged; 2. D. dnbius Miller; 3, D. ramosus 

 Spencer — a frond with a branch enlarged; 4, D. j^raegracilis 

 Spencer; 5, D. spinosus Spencer; 6. D.V problematicus 

 Spencer; 7, D. frondosus Spencer — a frond, natural size, and 

 branch enlarged. (Copied from Spencer) (*» 



S, 9. — 8, Dendrograptus dubius Miller — an incomplete frond; 9, 

 Dendrograptus raniosus Spencer — a frond branching uni- 

 formly 7 



10,11. — 10, Dendrograptus praegracilis Spencer; 11, Dendrograptus 



[ihaiuotheca, new species. View of the type-specimen '.» 



12. — Dendrograptus ontarioensis. new species. View of the most 



complete specimen 12 



13-15. — 13, Callograptus minutus Spencer ; 14, C. multicaulis 



Spencer ; 15, C. niagarensis Spencer. (After Spencer) 14 



16, 17. — 16. Callograptus minutus altus, new variety — view of the 



holotype; 17. C. strictus, new species in 



18. — Ptilograptus foliaceus Sjjencer. The type-specimen and a 



branch enlarged. (After Spencer) 16 



VII 



