326 Annals of the Carnegie Museum. 



men of Blastoidocriniis carcharicedens which he has so carefully 

 described and beautifully figured. The titles of Professor Hudson's 

 papers follow, and it should be noted that his work is still incomplete, 

 as he has still in hand a very considerable number of Cystids: 



"Contributions to the Fauna of the Chazy Limestone on Valcour 

 Island, Lake Champlain";^ "On Some Pelmatozoa from the Chazy 

 Limestone of New York";^° "Studies of Some Early Siluric Pelmato- 

 zoa."^^ 



Dr. Bassler, of the U. S. National Museum, several years ago under- 

 took the study of the Bryozoa of the Chazy, but has not so far found 

 time to complete the work. Although a considerable amount of 

 material is available, it is, like most of the other fossils of the Chazy, 

 in an indifferent state of preservation, and requires an unusual amount 

 of time for its elucidation. 



FlELD-WORK. 



Field-work on this formation by the writer practically ceased after 

 the summer of 1903, and I have, therefore, not so much as might be 

 expected to say in correction of my earlier work. Fortunately I 

 was able to spend a few weeks in 1910 and 191 1 on the Chazy of the 

 Ottawa Valley and in the region in Quebec north of the Champlain 

 Valley, and it proves necessary to make changes in our previous views 

 of the strata in those regions. 



Chazy in the Ottawa Valley. 



As the writer has set forth in detail elsewhere, ^^ the Chazy formation 

 of the "Geology of Canada," 1863, proved on further examination 

 to be composed of two formations, the lower one of which is of Upper 

 Chazy age, while the upper formation belongs to the Lowville-Black 

 River series, and is to be correlated with the Pamelia formation in 

 New York. This upper part corresponds to the Chazy limestone of 

 Logan and Ells, and very nearly to the Aylmer limestone of my papers 

 of 1905 and 1906. With the removal of this formation from the 

 Chazy, the following fossils must be removed from the list of Chazy 

 species: Ilelicotoma whiteavsiana, Raymond; Sowteria canadensis, 

 (Raymond); Modiolopsis breviusciila, Billings; Ctenodonta parvidens, 



' Report New York State Paleontologist for 1903-1904, pp. 270-295, pis. 1-5. 

 "> Bull, 107, N. Y. State Museum, 1907, pp. 97-131. Pis. i-io. 

 'I Bull. 149, N. Y. State Museum, 191 1, pp. 195-258, Pis. 1-7. 

 »2 Ottawa Naturalist, Vol. XXIV, 1911. P- 189. 



