STREPSIPTERA. 293 
to such elytra as we find in Atractocerus (Vol. I. p. 276 jig. 31.1.), 
Symbius (7bid. p. 291. Jig. 33. 16.), &c. Latreille, however, regarded 
them rather as analogous to the mesothoracic tegul, or basal wing- 
covers of the Lepidoptera; or as representing the lateral prolongations 
of the prothorax * observed in some species of Psychoda or Sceno- 
pinus. (Latreille, in Mém. du Mus. tom. vii. and Cours d’Entomol. 
p- 242.) The position of the second pair of legs, attached to the same 
segment as these organs (see Curtis, pl. 226. fig. K; and my figure 
of S. Childrenii, Giriff. An. K. pl. 59. fig. 1. 7,7, k, 1, m, n), clearly 
proves them to be mesothoracic. It is true that the great size of the 
only pair of the actual organs of flight of the Strepsiptera, might suggest 
an analogy with the large size of the wings of the Diptera, which are 
mesothoracic, but it appears evident to me that a more correct analogy 
exists with Phasma, Atractocerus, &c. 
The metathorax is of very large size, and of an oblong form, rounded 
behind, and projecting over the basal dorsal segments of the abdomen. 
The front part of its dorsum is divided by diagonal lines into four 
portions, the anterior of which bears some resemblance to the Coleop- 
terous scutellum (and is so named by Kirby, Linn. Trans. vol. xi. pl. 9. 
fig. 4. e), but it is, as I apprehend, a component part of the meta- 
thorax itself; the posterior part of the dorsum is dilated considerably 
at the sides (the dilated parts being termed femoralia by Kirby, 2. ¢. 
fig. 4. 1 7), with a deep anterior impression, and forms a very large post- 
scutellum. It is difficult to assign to these regions their strict analo- 
gous names, ‘The anterior scutellum-like piece is, however, considered 
by Perchéron (Gen. des Ins. Rhipipt. pl. 1.) as the praescutum; 
the two lateral triangular pieces following (or the lumbi Kirby, 
Lc. fig. 4. ff) as conjointly forming the scutum ; the middle triangular 
piece, with the apex pointing forwards (or the interlumbium K,, /. c. 
fig. 4. 2), as the scutellum ; and the large posterior piece (or the pro- 
scutellum K., /. ¢. fig. 4.) as the postscutellum. The transverse piece 
at the base of the latter is overlooked by Perchéron in his description, 
although clearly represented in his figure. It is named the postlum- 
bium by Kirby (J. ¢. fig. 4.7). The under-surface of the metasternum 
presents towards the base a strong inclination where the middle legs 
are lodged, which is succeeded by a flattened piece, dilated at the 
* Some of the large exotic Lamiides have a moveable spiniferous tubercle on 
each side of the prothorax. (Umbones K. and S.) 
u 3 
