122 
A DECADE OF AUSTRALIAN THYNNIDEOUS INSECTS. * 
GENUS AELURUS, KLUG. 
In my sketch of the generic arrangements proposed in this 
group of insects, given in pp, 102 and 103, I accidentally omitted 
to mention that Dr. Klug, in his Memoir in the Berlin Transac¬ 
tions for 1840, had described a new genus, founded upon two 
Brazilian species, which appeared to possess characters of higher 
value than those of the majority of the groups proposed by 
M. Guerin Meneville. 
Dr. Klug chiefly relied upon the structure of the trophi of the 
male for the characters of his genus, not describing the parts of 
the mouth of the other sex, nor noticing a character which at once 
distinguishes the genus from all the other Thynnideous insects 
which I have yet examined (except as mentioned below), namely, 
the homogeneous structure of the upper maxillary lobe, which, in 
the typical Thynnides, has the horny portion divided into two 
parts by a narrow transverse leathery connexion; a peculiarity, 
doubtless, connected with the structure of the parts of the lower 
lip, to which this lobe forms a defending sheath. That this division 
does not exist in Aelurus, I infer from Dr. King’s figure 16 a, 
compared with the same organ in the Australian insect, next to be 
described, which, notwithstanding some variation in the general form 
of the body, must, I conceive, be assigned to Dr. King’s new 
genus, w'hioh is thus showm to inhabit the Australian as w’ell as the 
South American Continent, a peculiarity in nowise surprising, when 
it is remembered that these are the two geographical seats of the 
whole group. 
AELURUS ABDOMINALIS. 
(Plate 77, fig. 5, and details.) 
Syn. —Agriomyia ahdominalis, Guerin, Mag. de Zool., 1842, p. 5. 
A. niger aureo-setosus, collaii punctis duobus transversis, scutello macula flava notato, abdomino 
(basi segment! primi excepto) pedibusque fulvo-rufescentibus. $ 
Long. corp. lin. 6J. Expans. alar. lin. 11. 
The head is black, transverse, and flat on the crowm, and finely 
punctured, the face is furnished in the middle with two small 
tubercles, at the sides of which the antennae are aflixed; the 
clypeus is slightly porrected, with its extremity truncate and 
yellow; the mandibles (fig. 5 i,) are fulvous, with the tips brown ; 
they are clothed beneath with long hairs; the labrum is small, 
entire, and strongly ciliated. (Fig. 5 a.) The antennae are long, 
slender, black, and filiform, with the tips acute, (measuring nearly 
