‘46 Contributions to Western Botany. [ZOE 
terus glomeratus the transition is complete. I have specimens. 
collected at Colorado Springs, Colo., whose seeds if taken from 
the plants would be referred to Coloptera Jonesi? by the appearance 
of the wings. This is No.-16 of my Colorado collection of 
1878, now distributed widely. In Co/optera_Jonesii the thickened 
part of the wing is rather firm (‘‘corky’’) and varies greatly in 
thickness, and usually has a thin edge beyond the corky part. 
In what must pass for Coloplera Parryi, from fifty miles south of 
Lee’s Ferry, Ariz., I find the wings much thinner than in 
Cymopterus glomeratus, and most of them with scarcely a trace of 
thickening, and in none of them would it be noticed by a casual 
look, but the plant is no doubt a true Coloptera otherwise, the 
more numerous oil tubes, the minute involucre, and the yellow 
flowers being the only distinguishing characters. In Cymopterus 
Slobosus the wings are thickened at the apex as much as in any 
Coloptera, but they are very spongy and soft. In Cymopterus 
megacephalus the wings at the apex closely resemble Coloptera 
Farryz in the variable thickening. The inconstant thickening of 
the wings is well shown in Coloptera Jonesit, where the dorsal 
ones are as thin as paper throughout, or nearly as thick as the 
lateral ones. At other times the dorsal wings are absent alto- 
gether, or only a filiform ridge; the shape of the seed is various; 
often it is very deeply concave, at other times it is scarcely 
concave; the lateral wings vary much; at times they are con- 
tracted around the deeply concave seed so as to form a cup like 
the variety cupulatum of Echinospermum Redowskti; at other 
times they are wide and flat. 
Another character relied upon by Coulter and Rose for 
Coloptera is the absence of an involucre (which is also true of 
Cymopterus &lomeratus). Unfortunately they overlooked this 
involucre in every case except C. Parryi, and I doubt not that it 
is found in that species also if plants fitting their description in 
every other respect are rightly referred there. In C. Newberryi 
and C. Jonesti I have seldom found it absent, but when it is 
reduced to a vestige as is often the case it would readily pass for 
a fold in the top of the peduncle and would lead one to think 
that the top of the peduncle was fleshy in the green plant, but 
that is never the case. Under the microscope this is at once 
