346 COLEOPTERA OF NORTH AMERICA. 



Dr. Chapiiis states (Gen. Col. Lacordaire, x. 375) that the 3d 

 tarsal joint, in Liua, is broad and entire, but we tiiid it deeply 

 bilobed in all of our species, including L. tremulse, which is 

 common to both continents. 



There has been an objection, which we think is ill founded, on 

 the part of several European systeniatists, to receiving the North 

 American species, placed by Mr. W. F. Rogers (Proc. Acad. Nat. 

 Sci., 1856, 30), in Doryphora. The species of Boryphora are 

 commonly conceived to be tropical insects, in which the meso- 

 sternum is more or less produced forwards. This character, as 

 we know in Anomala of the Scarabgeidse, has small significance, 

 and we would therefore prefer, in our desiitj to avoid unnecessary 

 multiplication of genera, to regard in this family and tribe, the 

 palpi as of more consequence than the mesosteruum for the defi- 

 nition of genera. We do this with the less reluctance, because 

 we do not observe in our species any particular transition between 

 the two sets of forms to which we ascribe the generic names above 

 given. 



The species of Chryaomela may be divided into sub-genera as 

 follows, according to Mr. Stal's monograph of the Chrysomel* of 

 America. 



Last tarsal joint with a tooth beneath ; claws approximate (elytra with 

 labyrinthine spots or stripes) Zygogramma. 



Last tarsal joint not toothed ; 



Prothorax with simple side margin (elytra with labyrinthine spots or 



stripes). Calligrapha. 



Prothorax with thickened sides (elytra without spots). Chrysomela. 



Group IV. — Gonioctenae. 



This group is represented in our fauna by two species of 

 Gonioctena. They are oblong oval insects of moderate size 

 (5-6 mm.). The elytra are punctured in striae, dull yellow, with 

 black spots ; the prothorax is also yellow, spotted with black. 

 The tibiae are obliquely and sinuately truncate at the apex, and 

 acutely toothed on .the outer margin. The 1st and 3d joints of 

 the tarsi are broad and spongy; the 2d joint is smaller and less 

 f^pongy ; the claws arc broad nearly to the tip, where they are 

 obtusely toothed. The southern limit of these species is Lake 

 Superior. 



