CHRYSOMELIDAE. 341 



cavities, so that in repose they present an appearance very similar 

 to the excrement of caterpilhirs. The tropical species are quite 

 large, but ours are both few and small. 



This tribe is distinguished by many peculiar characters, and 

 seems nearly isolated, though more closely related to the Crypto- 

 cephaliiii than to any other. 



The eyes are large and emarginate; antenna3 widely separated, 

 short, serrate, received in grooves. Prothora.x closely applied to 

 the base of the elytra, scutel wider behind and truncate, with a 

 small anterior cusp fitting in a notch of the base of the prothorax. 

 Elytra with large lateral lobes, suture denticulate. Fygidiuui 

 large, not covered. Prosternura wide in front, narrow behind, 

 separating the small front coxse, prolonged behind to the meta- 

 sternum ; coxal cavities very narrowly closed both before and 

 behind ; epimcra and episterna of metathorax not separated. 

 Legs compressed, received in excavations; claws appendiculate. 

 First ventral segment carinate, 5th large. 



Two genera occur in our fauna, which, except for convenience, 

 should probably be united : — 



Antennae serrate from the 5th joint at least. Chlamys. 



Antenna; serrate from the 6tli joint. Exema. 



The first genus is represented by several species in the Atlantic 

 region; the second by two in the Atlantic, one of whicli occurs 

 on the Pacific slope. 



Tribe VI.— CRYPTOCEPHALINI. 



In this tribe the prothorax is margined, closely applied to the 

 elytra behind, so that the form is robust and compact. The elytra 

 do not cover the pygidium. The eyes are large, and more or less 

 emarginate; the antennae widely separated, long and slender in 

 general, though sometimes (Monachus) shorter and subserrate. 

 The presternum is wide, the front coxse are rounded, not promi- 

 nent, and entirely inclosed ; the middle coxa^ are widely separated, 

 and the hind ones are transversely oval, and also widely sepa- 

 rated ; the intercoxal process is wide, the 1st and 5th ventral 

 segments longer than the others. The elytra have narrow epi- 

 pleurie, and are only moderately sinuate at the sides; the side 

 pieces of the metathorax are large. The legs are moderate, the 

 front ones frequently^ elongated, with thickened thighs; tarsi di- 



