Report of the State Geologist, 39 



the State of New York. Moreover the extension of the New York 

 formations beyond the limits of the state in the north, south and 

 west directions, gives other forms than those found within its 

 borders, and enlightens us in regard to the geographical dis- 

 tribution of genera and species, and the varying influences to 

 which they may have been subjected in these wider areas of their 

 original habitat. 



The importance of carrying out such views has been recognized 

 in the first part of the volume on the Inarticulate Brachiopods 

 where several genera, known only in the older rocks of Canada, 

 have been introduced and discussed. In the second part of the 

 work, that upon the Articulate Brachiopods, this requirement 

 became even more imperative, since a considerable number of 

 genera and species had been described from the older rocks 

 of Canada by Mr. Billings which had not been recognized else- 

 where. 



These forms moreover are very important, as lying at the 

 basis of our classification of the Articulate division of the 

 Brachiopoda. 



On the completion of the printing of Part I, before referred to, 

 I visited the Redpath Museum at Montreal and the Museum of 

 the Geological Survey at Ottawa for the purpose of studying cer- 

 tain imperfectly known forms, and of selecting specimens of such 

 genera and species as would aid in the illustration of the volume 

 in hand, according to its original plan. 



Through the kindness of Sir William Dawson I was able to 

 obtain, from • the Redpath Museum, a considerable number of 

 interesting forms for study and illustration. At Ottawa the 

 Director of the Geological Survey, through Mr. J. F. Whiteaves, 

 the Palaeontologist, granted every possible facility and assistance 

 for the study of the collections in the Museum of the survey, and I 

 was permitted the loan of a large number of specimens for the 

 study of species and genera long since described by Mr. Billings 

 from the older geological formations. These species, in the pro- 

 gress of study of the Brachiopoda, during recent years, have 

 become extremely interesting and important, as being the earliest 

 forms exhibiting the incipience of certain types of structure 

 which have become more ftilly developed in later geological 

 period^. The collections thus obtained have been of the greatest 

 importance in the preparation of the plates, the illustration and 



