THE THYNNIDEOUS INSECTS OF AUSTRALIA. 139 
THYNNUS (THYNNOIDES) GRACILIS, Westw. 
(Plate 83, fig. 2, 3.) 
3 Th. elongatus, totus niger, albo-setosus, alis hyalinis apicibus obscurioribus, coxis anticis sub- 
cochleatis. 
Long. corp. lin. 8. Expans. alar. lin, 14. 
Q piceo-nigra, griseo-setosa, abdomine nigricanti, segmentis posticis postice punctatis. 
Long. corp. lin. 5. 
Habitat prope Portum Adelaide. D. Fortnum. Mus. D. Hope. 
The male of this species (fig. 2) is of a more attenuated form 
than in the other Thynnoides. It is uniformly of a black colour, 
and clothed with silvery white hairs on the under-side of the body 
and legs. The head is transverse, black, and punctured with a 
tubercle between the eyes, at the sides of which the antenne are 
placed, a slender, straight, polished line running down it and the 
clypeus, which is considerably produced, convex, punctured, with 
the extreme lateral edges whitish ; the mandibles and palpi are 
black, the antennze rather slender, and about the length of the 
abdomen ; the thorax is black and punctured, the anterior lateral 
angles of the prothoracie collar are angularly prominent. The 
mesothorax is marked on each side with two impressed lines near 
the tegule, and within these are two abbreviated impressions, not 
extending to the anterior margin; the tegule are black. The 
abdomen is black, with the segments slightly constricted, each 
with a strong transverse impression across the base, and with a 
semicircular prominence on each side beyond the middle. The 
seventh segment is furnished with a small, circular, and rather 
deep impression near its extremity above, and with a minute 
tubercle on each side (fig. 2. a, 2 6), and the extremity of the abdo- 
men is armed with a slender spine, the tip of which is suddenly 
attenuated. The legs are slender, black, and clothed with grayish 
white hairs; the anterior coxe are dilated and slightly excavated. 
The abdomen beneath is strongly punctured; the anterior and 
second segment not angulated nor tuberculated in the middle, but 
the second and three following segments have on each side, towards 
the posterior margin, a very slight conical protuberance, with a 
slightly elevated line extending between them. The wings are 
hyaline, with the tips dusky, more especially at the extremity of 
the marginal cell. 
The female (pl. 88, fig. 3) is also rather more slender than those 
of the preceding species; it is of a pitchy black colour, the abdo- 
men being blacker than the rest of the body. The head is broader 
