406 Rev. H. Clark on the Halticidee of South America. 
Genus Cacoscetis, Chevr., Dej. Cat. 
D’Orb. Dict. Univ. Hist. t. i. p. 13. 
Elongata, parallela. Caput subproductum. Palpi mazillares, art. penul- 
timo subgloboso, ultimo acuminato producto. Thorax transversus, 
elytris distincte angustior, angulis anticis sat prominulis, posticis ro- 
tundatis, lateribus rotundatis et marginatis. E/ytra parallela, confuse 
punctata, marginata. Antenne filiformes, art. 4-7 subsequalibus. Pedes 
graciles; wnguiculis fortiter appendiculatis vel bidentatis. 
This form is not unlike the genus Disonycha, which in pattern is 
obviously different from it; besides however the distinctions of size 
and coloration, the species of Cacoscelis may be known by their 
somewhat narrower thorax and their appendiculated unguiculi. 
Two species only have been described. 
Cacoscelis famelica, Ol. Encycl. iv. 106, Ill. Mag. v. 124. 59. 
Cacoscelis marginata, Fab. Syst. Ent. 1822. 
Fervida, Ol. Ent. vi. 93 bis. 671. 
testacea, Ol. Encycl. vi. 586. 4. 
Abundant on certain trailing large-leaved plants at Rio Janeiro. 
Their jumping-powers only equal, or indeed do not equal, those of 
some of the species of Zema; when surprised, they can just toss 
themselves over the side of the leaf: the species is notable for its 
great variation as to size; I have examples in my collection, taken 
by myself from the same plants, ranging from 8 to 3} lines: the 
species varies also considerably in pattern, for I cannot but consider 
as a variety of it the Cayenne form (with two large macule on the 
thorax) C. binotata, Ill. Mag. v. 124. 60, C. famelica, OL., var., and 
also the Bolivian form (where the two thoracic spots are merged into 
one broad medial fascia) C. fasciato-collis of Chevrolat. 
Cacoscelis Feldneri, Ill. (Cat. Dej.). 
Cacoscelis venusta, De}. Cat. 
melanoptera, Germ. ? 
C. parallelo-ovalis, nigro-violacea, capite rufo: caput transverse foveo- 
latum, impunctatum, rufum: thorax leviter punctatus, rufus: elytra 
crebre et fortiter punctata, nigra vel nigro-violacea: antenne rufo- 
fuscee, art. 1-3 flavis: pedes et corpus subtus nigro-fusci. 
Long. corp. lin. 6-33, lat. lin. 83-13. 
Brazil, abundant. 
The following are among the undescribed species in my collec- 
tion :— 
