J. Hall on a question of Priority. 107 
merella. _ I wished to compare authentic specimens of the latter 
with Dinobolus, which under the name of Obolus Conradi had 
been stated by Mr. Dall to be a true Trimereila. The idea of 
designedly keeping Mr. Billings in ignorance of what I had 
done would have been simply silly and purposeless. 
The question regarding these oboloid forms had occupied 
my attention for a long time; and in 1862, I wrote to Mr. 
Davidson my views of 0, Conradi,* sending a description and 
figures. Thus this was no new idea of mine; but the progress 
of my work in 1871 required some action on my part in order 
to prepare the supplementary plates of vol. iv, Pal. N. Y., an 
these were among the things to be first done. Obolus Canaden- 
sis I did desire to see, for I had known since 1854 that it 
was a bew and distinct genus; and Mr. Selwyn did say that 
Mr. Billings was at work at O. Canadensis, but did not mention 
any Galt specimens or species. Mr. Billings says that his 
genus Obolellina “is intended to include at least one of the forms 
cribed” by him as “Obolus Canadensis.” It may include also 
Ruynozouvs, but I think that has not yet been shown by Mr. 
Billings’ figures. 
8 an explanation of applying on “two occasions,” 1 may 
Say that I understood Mr. a 
‘King no advantage of Mr. Billings in any way, for neither 
himself nor Mr, Selwyn had indicated his intention in regard to 
alt specimens, and those which I used had been in my pos- 
S€ssion since 1848 
* In my letter to i of date 31st October, 1862, I wrote—“I enclose 
= drawings of fret eet: as w genus of Brachiopoda. Tn some 
resbects it is like Oxotus, but is a large calcareous shell, in my opinion of quite a 
type. I had originally communicated the description in my Wisco’ as Ri va 
ard withdrew it. Please give me your opinion of it. 
Propose the name Conradia for this fossil.” : 
