TEEAMEROUS PLANT-BEETLES. 
167 
rules which we shall notice below. Labidomera contains one common 
species, the L. trimaculata , Fab., found on milk-weed. Myocoryna con- 
tains the destructive potato-beetle commonly known as the Dorypliora 
10-lincata, and the allied but much less common species J). juncta, and 
two other similar species found in Texas and Mexico. The generic 
name Doryphora , means a spear-bearer, in allusion to the pointed ante- 
rior prominence of the mesosternum, and was originally applied by 
Illiger to a similar group of insects from South America. But in our 
species the mesosternum is not produced to a point, and therefore M. 
Stiil, a Sweedish entomologist, has formed a new genus for them uuder 
the name of Myocoryna, from the Greek mus — to compress, and koruna , 
a club — the club of the antennae being slightly flattened. 
This is one of the exceptional genera with respect to color, being 
usually striped, but one species is wholly blue, and another is wholly 
red. Zygogramma, implying literally that the stripes are united or 
yoked together, contains a number of common species which are subject 
to considerable variation. Galligrapha, meaning beautiful writing, con- 
tains some of our most elegant beetles, distinguished by the numerous 
metallic marks and dots on their almost white elytra. The species are 
numerous and often variable. Mr. Crotch admits thirteen species as 
inhabiting the United States ; a few of them depart from the normal 
style of coloring, and resemble Zygogramma. The organic distinction 
between the two genera is, that in Zygogramma the claws are approxi- 
mate and the claw joint toothed beneath; and in Galligrapha, the claws 
are distant and the claw joint simple.* Chrysoniela proper is now re- 
stricted to a small number of dark colored species, some of which have 
a golden lustre. Oue species from Colorado and the neighboring States 
is black, with a yellow border to the elytra. 
Gastrophyza, Chev., — meaning abdomen inflated — alludes to the re- 
markably swollen condition of the abdomen of the females when tilled 
with eggs. It contains one of our prettiest and most common beetles : 
the G. polygoni, Linn., common to both Europe and this country. It is 
three-twentieths of an inch long, of a brilliant blue-greeu color, with a 
yellow thorax. It feeds upon the common knot-weed ( Polygonum aviep- 
lare.) Mr. Say described it as a rare insect under the name of Ghryso- 
♦It is a question whether in grouping certain insects— such, for example, as the Chrysomelules— the 
plan of coloration should uothavo more weight, in comparison with slight organic characters. It is 
evidently unnatural to separate such species, with striped elytra, as elegans, Olivier, and similis, 
Rogers, from the similarly marked Zygrogramma pulchra and exclamation™, Fab., and conjuncta, 
Rogers, aud unite them with the dissimilar and dotted group of Calligrapha, upon a character so 
variable, and therefore unimportant, as is the structure of the tarsal claws, in the whole family of 
Cli rysomelidm. 
Hut wo have been gratified to see, since the above was written, that Mr. Crotch, in his recent Check- 
list, of Coleoptera, has suppressed all these sub.geuora, and rocoguized them only as sectiojis of the 
original genus Ohrysoinela, of Linnmus ; a course which, it seems to us, might be profitably adopted 
with respect to many modern genera. 
