6o THE HAMILTON ASSOCIATION. 



However, the writer is more concerned in the Palaeontology of 

 the chert beds of the district, and undoubtedly they are exceedingly 

 rich in silurian organic remains, some of which are remarkably well 

 preserved, especially the phosphate shells, Graptolites and Hex- 

 actinnelid sponges. To the chert in solution which encased them 

 in some cases they owe their preservation. But on the other hand 

 it too often fills in the poriferous surface of the latter, as also the 

 cell mouths of the Bryozoojts, thereby rendering it impossible to 

 correctly classify the FenestellidcE for example, in accordance with 

 the recent sub-division of the family made by Paljeontologists, who 

 chiefly confined investigation to this particular class of fossils. 



As regards the general appearance, the Niagara chert Fenes- 

 tellidcB seems more perfect than any the writer has seen figured as 

 yet, the fan-like forms proceeding from a single stock. The cup- 

 shaped ones, like Fenestella Acmea (Hall), are well represented. 

 All but the latter are, however, valueless for description in conse- 

 quence of the concealment of the cell aperture. The Fenestella 

 Acmea is rather rare with us, but from its peculiar appearance it 

 cannot be easily mistaken for any other member of the family. The 

 same shape at a like horizon has, however, been remarked in a 

 Lichenalea, quite a distinct Bryozoon, perhaps undescribed. It may 

 be a fragment only has been figured, and as such would hardly be 

 recognized from the imperfect specimens under examination. The 

 writer may, perhaps, take an unjustifiable liberty in calling your 

 attention to the subdivision of these Palaeozoic Bryozoons by Prof. 

 Simpson, the best living authority on our sea mosses or mermaids' 

 laces. I underscore this, for on a previous occasion I was credited 

 quite erroneously through a printer's mistake with the discovery of a 

 " sea moose," which led to some few sarcastic congratulations on 

 the part of enquirers, and probably some unparliamentary language, 

 which could scarcely escape censure by the parsons if introduced here. 



A portion of the field near the corporation drain (the chief 

 locality for glaciated chert fossils) was ploughed up in autumn and 

 was expected to produce some rare specimens, only found as yet in 

 these beds here. The Cranidce family, from its great antiquity, is 

 of considerable interest, independent of the Crania, possessing the 

 singular property of adapting itself to the object to which it is 

 cemented. Dr. James Hall has figured and described some so 



