HAMIIvTON SCIENTIFIC ASSOCIATION 141 



to another in the museum case where another fragment was 

 preserved that the writer had not noticed. Possibly, like the 

 Fenestellidse of a similar horizon, the cellules may have 

 been filled in and completely obliterated by the flinty material 

 held in solution in the Ancient Silurian Sea. Our Hamilton 

 Chert holds many dwarfed specimens of the latter, but as 

 they never present the necessary cellules in order to determine 

 the proper classification, the writer merely collects specimens 

 whose forms appear to differ perhaps in a slight degree from 

 others that doubtlessly have been discovered in more perfect 

 preservation, either in the United States or elsewhere. 



The internal coiled spiral arm process is rarely preserved 

 in our Chert Bracheopods. I can only recall two or three 

 instances in " Atrypa retiadaris,^^ and until recently it was 

 not noticed, I think, in a " Spirifer^' where the conical spires 

 are directed outwards to the extremity of the hinge-line. 

 This class is not so common in the Chert as the various forms 

 of Strophomena^ but on reference to the useful and exceedingly 

 interesting work of my friend. Professor Chas. Schuchert's 

 "Fossil Bracheopoda, America," while Spirifer radiatus, 

 Sowerby, is credited as occurring at Hamilton, Ontario. 

 Spirifef Niagare?isis, Conrad, recognized by Billings, which 

 appears to be of more frequent occurrence, seems to be 

 omitted altogether. Probably this was owing to our own 

 neglect in not furnishing our friends in the United States 

 with a more complete list of Hamilton specimens. The 

 locality is credited with producing many of the fossils named 

 in the work in question, and when any deficiency is noticed, 

 the writer believes we ourselves are answerable for it. This 

 may be rectified in a future edition by transmitting absent 

 specimens to the author. Even under favorable conditions 

 the Geological Section may notice how very difl&cult it is to 

 distinguish Bryozoons in the weathered Chert of the Niagara 

 series here. All, as far as the writer can see, is of the same 

 appearance— colorless like the Matrix. The only exception 

 being one figured and described by Dr. Spencer some years 

 t>ack, Rhinopora venos?.. the veija-like portion of which is 



