18 CANADIAN FOSSILS. 
preceding, but the rachis is flexible, and is not known to be branched, 
while the slender alternating pinnule are flat and simple, as they have 
been observed in numerous individuals. ‘The specimen represented is even 
less curved than the usual condition of this species in the slaty Trenton 
limestone of Wisconsin. 
a 
Fig. 25. 
BUTHOGRAPTUS LAXUS: 
enlarged. 
Still more obscure, and perhaps remote in its analogies with graptolites, 
is the genus Jnocaulis, consisting of flattened scabrous stems, associated 
with Dictyonema in the shale of the Niagara formation, which, from their 
carbonaceous substance and apparent graptolitic texture, I have referred 
to the Graptolitide. 
Fig. 26. ° 
INOCAULIS PLUMULOSA. 
