SPEN'CER NIAGARA FOSSILS. 567 



elevations, arranged along the centre, or in subalternate order on 

 one face of the branch. Substance of the stipe and branch corne- 

 ous, solid, or tubular ; surface striated." 



A considerable number of species of the genus have been found 

 at Hamilton by Col. Grant and myself. In most cases the cell- 

 markings are poorly preserved, but many of the fronds, otherwise, 

 are in a good state of preservation, and several are very beautiful. 



Dendrograptus ramosus, nov. sp. 



Plate I. Fig. :5. 



Frond moderately flabelliform. The base of the frond arises 

 from a single stipe, and from near its summit most of the branches 

 originate, and moderately diverge above, with few bifurcations. 

 The texture is corneous, with the surface strongly striated. The 

 cellules are arranged along one of the margins of the branches, 

 and have angular openings, processes, or cell-denticles, marking 

 these openings as in fig. 3a, which is a branch enlarged. 



The largest frond is four centimetres liigh, exclusive of the 

 broad stipe, of which the length of a centimetre is preserved. It 

 expands above in straight radiating branches until the summit is 

 rather more than three centimetres across. The not-very-numer- 

 ous branches are comparatively stout, being about a millimetre 

 broad. The branches occasionally touch or overlap, but this 

 arises from the manner in which they were compressed in the 

 rock. This species is easily distinguished from any other of the 

 group that is obtained at Hamilton. 



Formatio7i and Locality . — This fossil is found in the more shaly 

 dolomites below the ''Chert beds" of the Niagara formation, at 

 the "Jolly-cut road," Hamilton, Ontario." 



Dendrograptus simplex, nov. sp. 



Plate I. Fig. 4. 



Frond erect, with strong branches originating from a lengthy 

 flexuous stipe, and diverging slightly above. The branches bifur- 

 cate only once or twice and are closely crowded together. Trans- 

 verse bars are apparent in one or two places. The texture is 

 corneous, with surface striated. On one side there are oval de- 

 pressions marking the cell-orifices ; these are nearly a millimetre 

 in length, and are situated about double that distance apart. 

 Rudimentary blanches are given oft' on each side of the stipe. 



