E. Billings on a Question of Priority. 271 
0. Galtensis, an imperfect cast of a dorsal valve of which was 
figured in my Pal. Foss., p. 108, in 1862. Neither of these 
species, so far as I know, has ever been found in New York. 
About three weeks after my paper was published, I received 
information from Thos. Davidson, Esq., of Brighton, England, 
the eminent Brachiopodist, that Prof. Hall had descibed 
+ 
number of geologists, professors in colleges, and scientific insti- 
five i ide 
anada. With a single exception, no one had received the 
oe agg Several expressed the opinion that the copy sent 
to 3 
the American Associations, a species or a genus must be pub- 
lished in a book, or in a journal circulating among scientific 
men. The book or the journal must be obtainable by the 
public, by purchase. If an author having a book in the press, 
should make an abstract of four or five pages, and give 
