[29 08g 
Fig. 56. 
a. Phacops ranw Green, (head shield); b. Pygidium of Proetus crassimarginatus (Hall); c. Pygidium of Dalmanites 
Boothii (Green). 
with from eight to ten segments. The entire surface is covered with rounded granules, which 
are of larger size on the anterior lobe of the glabella than elsewhere, 
Locality and Formation.—Hamilton Formation, Widder, and near Arkona, Township of 
Bosanquet. 
156. CYTHERE ? PUNCTULIFERA (Hall). 
Beyrichia punctulifera (Hall), Fifteenth Report on the State Cabinet, p. 111. 
“ Carapace valves minute, semi-oval, almost equilateral, the anterior end very slightly 
narrower, convex and abruptly bending downwards to the dorsal margin ; marginal rim well- 
developed, and sharply elevated on the ventral and lateral margins. The surface at the more 
prominent part above the centre, and just at the bending downwards towards the dor- 
sal margin, is marked by two very prominent nodes, which are nearly equi-distant from the 
margins and from each other. The entire surface is punctate with minute rounded pits.” 
(Hall, Loc. cit). 
Hall states that this is the most abundant of the Ostracoda of the Hamilton group, and 
I can hardly doubt that it is identical with a pretty little carapace, which is of very common 
occurrence in the Hamilton shales of Bosanquet, and which has the same punctated surface 
and marginal rim. If this be the case, however, the species can hardly be referred to Bey- 
richia, and our specimens differ in some important respects from Prof. Hall’s description. 
The form is not semi-oval, but somewhat elliptical, with a long diameter of about one line 
and a short diameter of half a line, and having the posterior extremity markedly broader 
than the anterior. The dorsal margins are rounded, not straight, and the nodes alluded to by 
Hall are very obscure.* The surface, on the other hand, is covered entirely with exceedingly 
minute pits. On looking at the surface-characters of this species, one can hardly help specu- 
lating as to whether it may not have been the larval form of a Trilobite, like Dalmanites 
Boothi or Phacops rana, though the nature of ornamentation is far from being precisely the 
same. 
Locality and Formation.—Common in the Hamilton Formation, Widder, Township of 
Bosanquet. 
CHAPTER. VII. 
APPENDIX. _ 
157. AuLopora (?) CANADENSIS (Nicholson). 
Alecto (2) Canadensis (Nicholson), Canadian Naturalist, Vol. 7, No. 3. 
I originally described this fossil from casts obtained from the Corniferous Limestone, and 
I referred it with doubt to the Polyzoan genus Alecto, giving the following description of 
it :— 
* On looking at the specimens of this speciesfrom the Hamilton Shales of Canandaigua, I find some to exhibit well 
marked nodes, whilst others, which in other respects appear to be precisely the same, agree with our Canadian examples 
in being either destitute of nodes or exhibiting them very obscurely. 
