No. 8.] SPENCER — GRAPTOLITES. 461 



less than -£§ of an inch wide, and in some specimens short abrupt 

 spine-like branchlets are given off. The texture is corneous. 

 Only a few specimens have been obtained, except in fragments. 

 Frond is about two inches high. It was first found by Col. Grant 

 in the Niagara limestones at Hamilton, Ont. 



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



Inocaalis (?) prohlematica, n. s. 



Plant-like, with numerous slender bifurcating branches, radiat- 

 ing more or less from a common centre, and resembling the 

 branches of rootlets; texture corneous with irregular corrugations. 



This species is of common occurrence, and is not easily mis- 

 taken for any other. The texture is not well preserved, appearing 

 often as mere stains of dark color on the surface of the stone. 

 Its relations are somewhat doubtful, but it is easily distinguished 

 from all the other species of the family by its root-like character 

 and slender branches (one-fortieth of an inch), often overlapping 

 each other in an irregular manner. It occurs abundantly in tha 

 Niagara limestones of Hamilton, Ontario. 



Genus Acanthograpsus, n. g. 



Gr. AkantJia, a thorn ; grapho, I write. 



Frond shrub-like, consisting of thick branches, principally 

 rising from near the base, with little divergence and some bifur- 

 cations. One side of the branches is furnished with prominent 

 spines or dentacles, which appear to mark the cell-apertures. 

 Texture corneous and indistinctly striated. This generic form 

 resembles Dendrograpsus, but it is stronger and more bushy than 

 species of that genus, and has conspicuous spines indicating a 

 different cell structure. 



Acanthograpsus Granti, n. s. 



Frond shrub-like, with thick branches principally originating 

 near the base. Some of the branches are bifurcated, and have 

 the ends dichotomous ; cell apertures on one side only, and in- 

 dicated by prominent spines which appear to be placed below 

 them. The branches are sometimes the sixteenth of an inch 

 broad, with spines in some places projecting the twenty-fourth 

 of an inch and ending abruptly. 



