1876.] Cooper's Helix in Colorado. 529° 
less than a fifteenth, of its former extent. The anterior supports 
are now relaxed, the wing assumes its natural position, the wing- 
cover closes down upon it, and all is snugly packed away. 
Although I have never experimented upon a living earwig, it 
will be apparent to any one who has attempted to expand a wing 
rendered flexible by artificial means, that the closure of the wing 
is produced by the mere elasticity of the parts. It is also alto- 
gether analogous to the process of duplicature in the cockroach, 
as carefully explained by Saussure, and it is difficult to ex- 
plain the process in any other way. The mode in which they 
are opened would be much more difficult to understand if it had 
not been observed by Charpentier and described nearly forty 
yearsago. The contraction of the extensor muscles attached to 
the hinder set of veins would undoubtedly cause the fan to ex- 
pand when once the double folding, transverse and longitudinal, 
had been overcome ; but it does not seem possible that they 
could cope with this difficulty. How then is it done? Accord- 
mg to Charpentier, simply by means of the forceps with which 
the extremity of the abdomen is always provided in both sexes ; 
the tip of the body is bent upward and the forceps used with 
steat rapidity and ease, first on one side and then on the other, 
asa sort of fingers, to bring the wings into the position which 
would allow the action of the thoracic muscles upon the base of 
the Principal veins. Nevertheless, it is difficult to conceive how 
is operation can be performed by those species whose forceps 
are as long as their body. 
COOPER’S HELIX IN COLORADO. 
BY E. A. BARBER. 
MONG the Helices, there is perhaps no species which pre- 
Sents greater diversity in form, size, and markings, than 
Heli Cooperi. Until recently, our knowledge has been some- 
What limited in regard to this beautiful and interesting western 
_ ‘Pecies ; but our information has been materially increased of late, 
by the results of the researches of the United States Geological 
Survey, During the summers of 1874-75, I found great quanti- 
"es of these shells throughout Colorado, in a variety of locations, 
Mad under variable conditions. I first discovered them in Middle 
w »a few miles from the Hot Sulphur Springs, or the settle- 
co known as Grand City, on the head-waters of the Grand or 
Gunnison River. As we were riding along through a severe hail- 
; Ol x, == NO. 9. 34 
