XXIX. ALYSON. 209 
which I have so often the pleasure to record, that I am in- 
debted for the sexes. He tells me, that the 9 (of which 
he took only two specimens) is much more rare than the ¢. 
This I should consider merely accidental, from his not hav- 
ing fallen upon the spot where the g¢ nidificates, the insects 
having been caught by brushing amongst the leaves of 
shrubs. I am led to this supposition by having experienced 
the same thing in the genera Gorytes, Arpactus, and Nys- 
son; but when I have discovered the nestling-place of the 
@, she has generally occurred in equal abundance with 
the ¢. 
b. The mandibles moderate, arcuate, bidentate at their ex- 
tremity ; antennz sometimes slightly increasing towards their 
apex. 
Genus a al eS Latr. 
Heap transverse, in some much depressed in front; eyes oval, 
lateral; stemmata placed upon the vertex, very forward, and 
generally in a curve; antenne subfiliform, inserted at the base 
of the clypeus, longer in the males than in the females and 
very slightly thickened towards the apex, in the former gene- 
rally as long or longer than the thorax; the clypeus transverse, 
rounded in front; the /abrum exserted, transverse, anteriorly 
rounded and fringed with long setz ; mandibles bidentate, the 
teeth rather obtuse. The THorax ovate; collar transverse, 
linear; scutellum transverse, quadrangular; the metathorax 
with a triangle at its base, and obtuse or gibbous, and trun- 
cated at its extremity; the superior wings with one long narrow 
marginal cell and four submarginal cells, the first nearly as long 
as the two following—the second much narrowed towards the 
marginal and receiving both the recurrent nervures—the third 
quadrangular, the exterior somewhat rounded—the fourth extend- 
ing to the apex of the ming, although sometimes only obsoletely 
P 
