MIMOPEUS II1 
the proepisternum and the deflexed part of the pronotum, which are completely 
fused together. Proepisternum finely punctate, each puncture bearing a short seta, 
interstices sometimes bearing small granules. 
Ventral surface of mesothorax (Fig.4). Mesosternum considerably depressed 
anteriorly, depressed part bearing a median longitudinal ridge and more or less 
setose. Intercoxal process (Fig.30 more detailed than in Fig.4) moderately broad, 
finely punctate, with distinct submarginal grooves. Mesepisternum with similar 
sculpture and clothing to depressed part of mesosternum. Mesepimeron (m.epm.) 
closing mesocoxal cavity outwardly by its inner edge, smooth and finely punctate. 
Trochantins of mesocoxae exposed (Fig.73). 
Ventral surface of metathorax (Fig.4). Metasternum short, about three times wider 
than long, intercoxal processes as in Fig.4, submarginal grooves near anterior and 
posterior edges. Median longitudinal suture extends about two fifths distance from 
posterior edge towards anterior edge. Finely punctate, lateral punctures bearing 
fairly long yellow setae, surface generally smooth with a few transverse and 
longitudinal wrinkles, sometimes with small granules. Mesepisternum and mete- 
pimeron smooth, shining, finely punctate, with short yellow setae. 
Metendosternite (Watt 1974: 443,fig 43). This structure has been little considered 
in the systematics of Tenebrionidae. Crowson (1938, 1944) illustrates 5 species, all 
of which, however, appear to be either particularly primitive (Tribolium) or 
specialised. A fairly generalised type 1s that of Tenebrio molitor (Watt 1974, 
fig.43), which is used here as a basis for comparison. 
Mimopeus opaculus and M. elongatus have been examined for the structure of 
their endoskeleton, and their metendosternites are as illustrated in Fig.8. In these, 
a stalk of moderate length is present. Arms fairly long, quite slender. Anterior 
tendons arise about half way between base and apex of arms. Ventral process ot 
arms reduced, no “lamina” present. The same strengthening ridges of the arms are 
present as in Tenebrio, and the main differences are in the position of origin of the 
anterior tendons, in the relative proportions of the arms and stalk, and in the more 
greatly reduced ventral process of arm in Mimopeus. Note that in Tenebrio the 
anterior ridge joins the ventral flange at its apex, but in Mimopeus the junction is 
behind the apex. 
The slight differences between the metendosternites of M. elongatus and M. 
opaculus may be due mainly to the difference in size of the beetles, or they may 
have some significance in intrageneric systematics. 
Abdominal sternites (Fig.4.) Sternites 3-7 (i.e. first 5 visible sternites) heavily 
sclerotised. Intercoxal process of sternite 3 fairly broad and rounded anteriorly. 
Submarginal grooves present parallel to anterior margin of sternite 3 and near 
lateral margins of sternites 4 and 5, and usually of sternites 6 and 7. Each of these 
sternites bears macropunctures, fine setae and micropunctures. Intersegmental 
membranes visible between sternites 5 and 6 and between 6 and 7. Sternite 8 
slightly sclerotised. In males apex emarginate. In females apex coming to a single, 
fairly blunt point. Ventral surface of sternite 8 in both sexes covered with fine 
setae, these are especially long on the apices in the male. 
