124 



Pig. 56. 



a. Phacops rcma 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 ju&t 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, LOG. 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, nqj 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. ATTLOPORA(?) CANADENSIS (Nicholson). 



Alecto(?) 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 Aleclo, giving the following description of 



it: 



* On looking at the specimens of this species from 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 

 5n being either destitute of nodes or exhibiting them very obscurely. 



