XXVII. CEMONUS. 199 
species until recently, upon examining my this year’s 
[1836] captures, I found it intermixed with the species of 
the genus Diodontus. It is further distinguished from all 
Van der Linden’s and St. Fargeau’s Pemphredones, by not 
having a silvery pubescence on the face in either sex, and 
which is a remarkable distinction in this family. 
Genus XX VII.—Cemonvs. Jurine. 
Heap large, subquadrate ; eyes small, oval, placed at the lateral 
angles of the head and very distant; antenne geniculated, 
inserted at the base of the clypeus but not approximate ; the 
anterior margin of the clypeus acutely produced in the centre ; 
the /abrum small, entire, triangular, deflexed laterally ; the man- 
dibles spoon-shaped, quinquedentate, the third inner tooth very 
obtuse and the largest, the rest acute. The THoRAx ovate ; 
the collar transverse, linear; the dorsolum somewhat gibbous ; 
the scutelium transverse, quadrate, the posterior angles round- 
ed; the metathorax obtusely truncate ; the superior wings mith 
one marginal and two submarginal cells, the first submarginal 
oblong receiving both the recurrent nervures, the first towards 
its centre, and the second tonards its extremity—the second sub- 
marginal almost square, slightly wider towards the marginal 
cell; the legs moderately long. The aBpomeEn oval, petio- 
lated ; the petiole slightly curved and not longer than the first 
segment of the abdomen. 
Type, C. unicolor. F. 
+44 This genus was formed by Jurine for the insects 
which Latreille had previously named Pemphredon, and 
which he divided into two families; it consequently fell 
into a synonyme of that genus as they stood prior to my 
separation of them as his division was not admitted by sub- 
sequent writers ; I therefore think it but just to Jurine to 
re-establish his genus by the type he intended for it, al- 
though by some accident he figured the Pemphredon lu- 
gubris, F., by that name. This genus consequently con- 
