( 30 ) 
terior feet nutatory, base of the thighs naked ; antennae e- 
leven jointed, at least as long as the head and thorax, fili- 
form ; sen tel distinct ; terminal joint of the palpi somewhat 
compressed at tip and emargiiiate. 
Observations. 
This genus differs from other genera of this family in the 
character of the emargiiiate palpi, excepting the genus No- 
terus which is destitute of an apparent scutel and the emar- 
gination of the palpi is confined to the labiales, The name 
is derived from the words co]pto I cut, and tome joint or ar- 
ticulation, in allusion to the form of the palpi. 
Species. 
C. serripaipus^ Yellowish ^ elytra brownish varied with 
whitish. 
Inhab. Mexico. 
jBofZy oblong- oval, honey-yellow : head black on the pos- 
terior margin : labial palpi with the penultimate joint cre- 
nate or bituberculate before : thorax on the middle of the 
anterior and posterior margins broadly black : elytra broAvn- 
ish, with very numerous, minute honey-yellow points ; two 
very slightly impressed strjse, with punctures hardly dis- 
tinguishable from minute inequalities of the surface, and an 
indistinct part of a series of hardly impressed punctures 
each side; from the base near the scutel proceeds a whitish 
broad vitta one-fifth of the length of the elytra, bifid at tip^ 
from the humeral base to the tip proceeds a broad, interrupt- 
ed and somewhat irregular vitta also whitish : venter pi- 
ceous. 
Length less than three-tenths of an inch. 
This insect was obtained on the estate of the Conde del 
Regia about 10 leagues N. E. of the city of Mexico by 
Wm. Bennett and presented to me by Mr. Wm. Maclure. 
It cannot be the Dytiscus circumscriptus, Germ, which is 
^^breviter ovali.^^ 
LACCOPHILUS, Leach. 
t. L. macwZostts, Say, Trans. Amer. Philos. Soc. Since 
described by Germar, also under the name of mdeult)sus. 
Sp. Gen. p. 30. 
HYPHIDRUS, Latr. 
H. punctatus, Say, (Laccophilus) Journal of the Acad. 
Nat. Sc. 
