A. C. Twining—Aurora of Feb. 4th, 1872. 273 
comparison. Mr. Selwyn, when he lent the specimens, gave 
him notice of the correspondence then going on between Mr. 
Davidson, Mr. Dall and myself, and also that I was at work 
on O. Canadensis. Prof. Hall should have notified Mr. Sel- 
wyn that he was engaged on the Canadian specimen, or he 
should have published his genus. He did neither, and it re- 
mains for the public to decide whether he was right or not. 
It appears from Mr. Davidson’s letters, that Khynobolus was 
to have been brought out in England, in a paper which he (Mr. 
Davidson) and Prof. King had im preparation on the TZrimerella 
oup. 1 knew nothing of this We can now see why it was 
kept so quiet in America. Fortunately, Mr. Davidson delayed 
his paper for a box of specimens I had promised him, and these 
I could not well spare until my own paper was finished. Mr. 
Davidson appears to be under the impression that Prof Hall’s 
pamphlet has been regularly published. 
hat is stated above, can be authenticated by a number of 
letters written by Prof. Hall, Mr. Davidson, and some of the 
best scientific men in the United States. 
Montreal, 26th Feb., 1872. 
Arr. XXXVIL—The Aurora of February 4th, 1872; by Prof. 
ALEX. C. TWINING. 
gh sition of the zone. No “aurora’s bow” ever 
a 
€ like consistence or constitution, or the like color and time 
of continuance, or the like invariableness of position. Indeed, 
‘tis a fact which the writer can avouch from his own observa- 
tons, that—excepting the extreme western parts, which he did 
hot observe early in the evening—the zone maintained essen- 
Hally the same extent and situation, relative to the stars, at a 
uarter past ten o’clock in the evening which it had here at 
€w Haven at a quarter before seven. The same fact, it 
Aw. Jour. ng wie Sunres, Vou. III, No. 16.—APRIL, 1872. 
