THE THYNNIDEOUS INSECTS OF AUSTRALIA. 145 
The male (pl. 82, f. 5) is entirely black and slightly clothed with 
grey hairs, the head is nearly round and strongly punctured ; the 
clypeus but slightly porrected ; the labrum pitchy and setose ; the 
mandibles are pitchy red, with the base and apex black ; the thorax 
is oblong, truncated in front and rounded at the metathorax ; the 
pro- and mesothorax are regularly punctured, but the metathorax is 
very delicately rugose. The abdomen is sub-depressed, fusiform and 
thickly punctured, especially at the base of the segments, the basal 
segment with a deep longitudinal impressed line: the three following 
segments are marked with a rather deep transverse impression 
across the base, and have a slightly raised space on each side, near 
the hind margin ; the extremity is destitute of spines or tubercles, 
the under side is also simple and thickly punctured ; the legs and 
antenne are slender and black, and the hyaline wings, nearly 
colourless, but strongly iridescent, with the veins and stigma black. 
The female (pl. 82, f. 6) is entirely fulvous, the fifth segment of the 
abdomen alone being of a darker colour; the whole surface of the body 
is remotely punctured, the punctures being oblong, but minute; the 
head is oblong and depressed, with a slight longitudinal impression 
in front, extending to the bifid projection at the sides of which 
the antennze are placed; the mandibles, unlike those of Sclero- 
derma, are curved and acutely pointed at the tips, with a small tooth 
on each side, near the extremity ; the thorax is rather longer than 
the head, the mesothorax being the widest part, the sides of which 
are swollen; the metathorax is narrowest at the base, and rather 
slanting. The abdomen is long, entire and uniform, the second 
segment exhibiting none of the peculiarities of the true Thynni: the 
legs are short, the posterior femora and tibiz dilated, the latter 
furnished on the outer margin with short strong sete, thus differing 
entirely from the feet of the Scleroderme, which are not fossorial. 
The plant represented in Plate 83 is the Australian Tetratheca 
Thymifolia of Smith. 
In addition to the various memoirs upon the Thynnides noticed 
in the previous pages of this work, I have to add that Dr. Erichson, 
in his Memoir on the Insects of Van Diemen’s Land, published in 
the Archiv. fur Naturgeschichte for 1842, has described four 
additional species of Thynnus, together with a new genus named 
Ariphron, founded upon an apterous female closely allied to 
NO. XXII.—1sf NOVEMBER, 1844. lt 
