458 THE CANADIAN NATURALIST. [Vol. viil. 



Without further mention of the interesting associations of the 

 Graptolites at present, the writer respectfully submits the notice 

 of a few species found at Hamilton. 



Genus Dictyonema, Hall, Palaeontology of N. Y., Vol. II. 

 D. retiformis, Hall, " " 



D. gracilis, Hall, " " " 



D. tenella, n. s. 



Genus C'llyptograpsus, n. g. 

 C. cy a th if or mis, n. s. 

 C. subretiformis, n. s. 



Genus Rhizograpsus, n. g. 

 Rh. bulbosus, n. s. 



Genus Inocaulis, Hall, Palaeontology of N. Y., Vol. II. 

 I plumulosa, Hall, " " '< 



I. bella, Hall & Whitfield, Palseontology of Ohio. 

 /. (?) problematical, n. s. 



Genus Acanthograpsus, n. g. 

 J.. Grand, n. s. 



Genus Ptilograjjsus, Hall, Can. Organic Rem. Decade II. 

 Pt.foliaceus, n. s. 



Genus Callograpsus, Hall, " " " 



(7. Niagarensis, n. s. 



Genus Tlwnnograpsus, " " " 



7%. Bartonensis, n. s. 



Genus Dictyonema, Hall, Palaeont. N. Y., Vol. II. 

 Dictyonema tenella, n. s. 



Frond cyathiform in growing state, but usually circular, 

 although occasional specimens have a flabellate form in the rock. 

 The branches are uniform, nearly parallel, and radiate from the 

 centre with very few bifurcations; in width they vary from yl^ 

 to -gL of an inch, but uniform in the same specimen. The 

 branches are connected at short intervals by transverse dissepi- 

 ments; while the margin of the frond is remarkably constant. 

 The surface is striated, and the texture has a corneous character 

 like that of the other species of this group. 



As the connecting filaments are very fine, owing to imperfect 

 preservation, they are not always distiuct over the whole surface 



