38 INSECTA. 
narrowed behind, but not abruptly, and without a neck at its base. 
Many of these Heteromera avoid the light. This division will com- 
prise the three following families. 
FAMILY I. 
MELASOMA. 
This family consists of unmixed black or cinereous coloured In- 
sects, (from which is derived the name of the division,) mostly apte- 
rous, and frequently with soldered elytra. Their antenne, entirely 
or partly granose, almost of equal thickness throughout or slightly 
inflated at the extremity, and the third joint wholly elongated, are 
inserted under the projecting edges of the head. The mandibles are 
bifid or emarginated at the extremity; the inner side of their maxillee 
is furnished with a corneous tooth or hook, all the joints of the tarsi 
are entire, and the eyes oblong and but ‘very slightly prominent, a 
circumstance which, according to M. Marcel de Serres, indicates 
their nocturnal habits. Almost all these Insects live on the ground, 
either in sand, or under stones, and frequently in cellars, stables, and 
other dark places about our habitations. 
According to M. Dufour—Ann. des Sc. Nat. V. p. 276—the biliary 
vessels are inserted into the inferior face of the cecum by a single 
trunk, resulting from the confluence of two very short branchés, 
formed by the union of three biliary vessels. The bile is yellow, 
sometimes brown or violet. The alimentary canal—Ann. des Se. 
Nat., III, p. 478—is long, and its length in our first tribe, or the 
Pimeliarie, is thrice that of the body; the cesophagus is long and 
leads to a crop smooth or glabrous externally, that is more developed 
in these latter Insects where it forms an ovoid sac lodged in the pec- 
tus; it is marked internally with longitudinal plice or fleshy co- 
Jumns, terminating in some—Frodii, Pimelie—near the chylific ven- 
tricle, at a valve formed of four principal corneous, oval, and conni- 
vent parts; the chylific ventricle is elongated, flexuous or doubled, most 
commonly covered with little papille resembling projecting points, 
and terminated by a small collar, callous within, which receives the 
first insertion of the biliary vessels. The same anatomist has ob- 
served in some subgenera of this family—Blaps, Asida—a salivary 
apparatus, consisting of two floating vessels or tubes, sometimes per- 
fectly simple—Astda—and at others irregularly ramous—Blabs ;— 
he is also convinced that they exist in the other Pimeliariz. M. 
Marcel de Serres—Observations sur les usages des diverses parties du 
