17 



third, ilic clvpciis. 'I'lic rclalioii of llicsr pints is rrmaii\iil)ly consliiiil in all 

 the Lcpidoiitcra. In llic l>()iiil)y(:i(i;i' tlicrc is a !,M-cat variation in all the 

 irroups; but in the Xoclnidiv Ihry arc vciy constant. The relalivp pidpoition 

 of (licsc ])i('C(^s is very oonstaiil in the I'lialaMiida', so ninch so that they arc; 

 scldiiin of much practical nse as jrcncric characters. 



The occij>iil, or l)aso of the licad, on llic vcitcx, is separated by sulur<' 

 from the orbits. It is usually very short (antero-posteriorly) in (lie median 

 line of the head, widening out where it touches the orbits. 



The ejiicni/iii/iii is very small and narrow, often not extending on eillier 

 side to the orbits. It is conlracled in front, oxfisiding between the insertion 

 of the antennjv, and is moderately convex. 



'['he, cJupvKs occu[)i(;s nearly the entire IVont of the head, and is so large 

 as to carrv the insertion of the antcnn;"c well ti|) on the vertex. It is usually 

 considerably longer than broad, especially in many of the higher genera; 

 while in Eupltliccia it is shorter; so, also, in J>oii/m/a. The sides nvo often 

 l)arallel, and often also converge a little anteriorly; tlie base is deeply sinuous, 

 beins excavated on each side to receive the antennir. 



How these pieces vary in several of the typi:;al genera may be seen 

 from the following notes and figures, beginning with the lower geiu'ra and 

 ascending to the liigher: 



Eupitlu'cia miscfulata (pl.G, fig. 19). — In this species, the occiput is longer 

 than usual, and as long in the middle as on the sides, being transversely 

 oblong. The ei)icranium is equiluterally triangular, though a little shorter 

 than broad. The clypcus is considerably longer than broad, the sides slightly 

 converging. It is rather full on the surface. 



I'etrojihora dlcersiUiienta. — Head much narrower than in the higher sub- 

 families. Eyes full and globose; both the occipital and clypeal regions mon; 

 elongated than usual. Occiput long, being one-fourth as long as wide, and 

 of even length throughout, but near the orbits extending anteriorly in a slight 

 point. Epicranium rather small; subtriangular ; hinder edge a little more 

 convex than usual. Antennjie moderately far apart. Clypeus nearly square, 

 a little longer than broad ; siiles straight and parallel. No orbital region ; 

 front of clypeus well rounded, convex; man(lii)les well developed; lal)rum 

 minute; and tongue well devclo])ed as usual. 



Hi/drui nnduhda. — In some respects a mean between Pctrophorn and 

 Phlbahiptenjx. Eyes less full. ()('cii)ital region not so wide as in Pctrophora ; 

 3 P II 



