( S9 ) 
COLYMBETES, Clairv. 
1, C, tcenioliSf Say (Dytlscus) Trans. Amer. Pliilos. Soc. 
In Mexico is a variety, being smaller. The specimen is a 
male and proves that the species must be placed in the pres- 
ent genus. It was taken in the E-iver beyond Vera Cruz. 
2, C. gutticollis. Thorax yellowish with four black spots | 
bead black, anteriorly and band of the vertex yellow. 
Inhab. Mexico. 
black; a transverse yellowish band between the 
nearest points of the eyes ; a dilated yellowish triangle oc- 
cupying alt the anterior part of the head, the apex being at 
the middle of the face : antenim and faljpi honey -yellow, 
dusky at their tips : thorax honey-yellow, anterior margin 
blackish ; posterior margin dusky ; four large black 
spots in a transverse series, the two intermediate ones nearer 
together : elytra honey-yellow with niinute black points more 
or less crouded so as to give a dusky, sometimes almost black- * 
ish appearance ; lateral margin destitute of black punctures, 
but with a black line on the posterior curvature ; at base, 
particularly the humeral base, destitute of the black punc- 
tures; three regular series of small black dots: beneath 
black; pectus, feet^ and epijileura yellowish. 
l^ength over two-fifths of an inch. 
Taken in the River beyond Vera Cruz. 
It is about the size of the C. adspersus, F. which it con- 
siderably resembles, if we except the thoracic black dots. 
2. C fenestralis. Say. Trans. Amer. Philos. Soc. Since 
described by Germar under the name of biguttulus, Sp* In- 
sect, p. 29. 
S, C. interrogatus, Fabr. Syst, Eleut, 
C. venustus, Say, Trans. Amer. Philos. Soc. When 
describing this species I stated that it ^%ay probably prove 
to be the interrogatus of Fabricius,’^ Of this I have now 
80 little doubt, that I venture to reject the name I then pro- 
visionally gave and to adopt the true, or anterior name. 
Dejean is also of the opinion that it is the interrogatus, 
F.— ^Hturm, however, considers it distinct. 
COPTOTOMUS, Nob. 
Tarsi distinctly five jointed ; basal joints of the anterior 
pair of the male subequally dilatedor gradually tapering; pos- 
lerior nails appressed together and apparently single ; pos- 
