AULACOSCELIS.—HZMONIA. 7 
depression at the sides of the thorax. The thorax is without a transverse basal groove 
in either sex. The first abdominal segment is not three times longer than the second 
(as Chapuis says of the type), but is scarcely twice as long, and the whole underside is 
covered with thin yellowish pubescence. 
Fam. DONACIIDE. 
(To precede the Crioceride, p. 2.) 
We have now to record from Central America both the known genera of this family. 
DONACIA. 
Donacia, Fabricius, Syst. Ent. p. 195 (1775). 
This genus contains a large number of species, mostly inhabitants of the Palearctic 
and Nearctic Regions, but also widely distributed in the warmer parts of the Old World. 
South America has apparently no representative, and the southern limit of the genus 
in the New World is in Cuba or Mexico. The single species here added to the Central- 
American fauna is a well-known North-American form. 
1. Donacia cincticornis. (Tab. XXXV. fig. 11.) 
Donacia cincticornis, Newm. Ent. Mag. v. p. 391 (1838)’. 
Var. Donacia rufipennis, Lac. Monogr. in Mém. Soc. Liége, iii. p. 110 (1845). 
Hab. Nortu America! ?.—Mexico, Toxpam (Sal/é). 
I am not able to find any difference of importance between the Mexican specimens 
and one from North America contained in my own collection. The elytra are without 
transverse rugosities, except at the sides, and their apices are truncate; they are 
obscure brownish-eneous on the disc, this colour changing to a more metallic green at 
. the sides. The thorax is slightly broader than long, without distinct angles, nearly 
smooth and impunctate, and with a distinct central groove. The antenne are brownish, 
each joint being dark at its apex, the fourth being nearly twice the length of the third. 
The posterior femora extend slightly beyond the elytra and have a minute anterior and 
a distinct posterior tooth. 
HA:MONIA. 
Hemonia, Latreille in Cuvier’s Régn. Anim. v. p. 186 (1829). 
This genus contains about a dozen members, all from Europe or North America. 
The different species are attached to water-plants and are more aquatic in their habits 
than Donacia. One inhabits Mexico; it has lately been obtained by Herr Hoge in 
great numbers, in the lagoons in the vicinity of the city of Mexico. 
