TERAMEROUS PLANT-BEETLES. 167 



rules which we shall uotice below. Lahidomcra contains one coiiunon 

 species, the L. trhnacidata, Fab., found on milk-weed. Myocoryna con- 

 tains the destructive potato- beetle commonly known as the Doryphora 

 lOlineata, and the allied but much less common species i). juneta, and 

 two other similar species found in Texas and Mexico. The generic 

 name Doryphora, means a spear-hearer, in allusion to the pointed ante- 

 rior prominence of the mesosteruum, 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 under 

 the name of Myocoryna, from the Greek mus — to compress, and horuna, 

 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. Zyyofiramma, implying literally that the stripes are united or 

 yol-ed fo(/('flier, contains a number of common species which are subject 

 to considerable variation. (JalligrapliK, 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 Zygofiramma. The organic distinction 

 between the two genera is, that in Zygoyramma the claws are approxi- 

 mate and the claw joint toothed beneath; and in Calligrapha, the claws 

 are distant and the claw joint simple.* Chrysomda proper is now re- 

 stricted to a small number of dark colored species, some of which have 

 a golden lustre. One species from Colorado and the neighboring States 

 is black, with a yellow border to the elytra. 



Oastrophyza, Chev., — meaning abdomen inflated — alludes to the re- 

 markably swollen condition of the abdomen of the females When filled 

 with eggs. It contains one of our prettiest and most common beetles: 

 I lie G. polygoniy Linn., common to both Europe and this country. It is 

 three-twentieths of an inch long, of a brilliant blue-green color, with a 

 yellow thorax. It feeds upon the common knot-weed {Polygonum avicu- 

 tare.) Mr, Say described it as a rare insect under the name of Chryso- 



*It is a question whotbor in jrroupin^ certain insects — such, for example, a« the Chrysoinelidos — the 

 l>lan of coloration should not have more weij;ht. in comparison with slight organic characters. It ia 

 evidently nnuatiiral to separate such sitecies, with striped elytra, as eleijnns. Olivier, and gimilis, 

 Rogers, from the similarly marked Ziifjrojratnma jndchra and erclamalionix. Fab., and coiijuncta, 

 Rogers, and unite them with the dissimilar aud dotted gixjup of Calligrapha, upon a character so 

 v;irial>le, and therefore unimportant, as is the structure of the tarsal claws, in the whole family of 

 ( liry.somolida'. 



Hut we have been graf ifieil to see, since the above was written, that Mr. Cnjtch, in his recent Check- 

 list of CoU'optera. has suppressed all these 8uV)-genera, and recognized them only as sections of the 

 original genus Chrysomela, of Linna-us ; a course which, it seems to us, might be profitably adopted 

 with respect to miUiy modern genera. 



