6 BURGESS ON THE ANATOMY 



resent the post-scutellum. A continuous ossified collar encircles the prothorax beneath, 

 composed of the episternal and sternal elements fused into one piece. Behind and beneath 

 this collar are attached the long cylindrical coxae of the first pair of legs. Epimera are 

 not recognizable. 



A broad membranous neck separarates the prothorax posteriorly from the mesothorax 

 (ii.). The scutum (s.^) in this segment is very large, oblong, and vaulted. In front there 

 is a rather deep pentagonal depressed area, with a rounded central portion, fitting against 

 the articular surface between the meso- and pro-thorax, as already described. This area is 

 perhaps the praescutum, and is, as it were, wedged into the scutum. Just below the ante- 

 rior corners of the scutum are attached, by a small stalk, two leaf-like epaulets, the pata- 

 gia ^ {pt.). These are nearly semicircular in shape, with a conical piece projecting back- 

 ward from the lower corner. The great development of the patagia is characteristic 

 of the Lepidoptera. Behind the scutum, which is slightly emarginated posteriorly, is 

 the lozenge shaped, tumid scutellum {sni?), whose lateral corners project under the base of 

 the scutum. A narrow membranous area separates the scutellum from the post-scutellum, 

 {psm}), which is an arch shaped piece mostly concealed by the postthorax ; it sends a 

 long process forward on each side under the scutum and reaching the epimera, while 

 behind it extends into the interior of the thorax for the attachment of the great thoracic 

 muscles (see fig. 2, l.m.). The episternum {eps?) is triangular, with two sides convex, its 

 base resting on the sternum {st.^}, which is an irrregularly six-sided, transverse piece cov- 

 ering the chest. The sides of the prothorax behind the episterna are formed by the 

 epimera [epm?) shaped something like an hour-glass in outline, being emarginated deeply 

 above for the sub-alar membrane, and, beneath for the coxae [ex?) of the second pair of 

 legs, which are immovably united with the epimera and sternum. 



The scutum, [sm,?) of the Tneta-thorax (m.) is divided into two lateral triangular wedges 

 somewhat like the prothoracic lobes, between which in front the scutellum and postscutel- 

 lum of the mesothorax are wedged, and behind the triangular scutellum, of its own seg- 

 ment (sTO.^). The episterna {ejjs}) and the sternum show no dividing suture, and embrace 

 the base of the coxae above and in front; while, in similar fashion, the epiimera {epm?) 

 send projections backwards above and behind. The shape will be better understood from 

 the figures, than from any description. 



The roots oi wings [w} andio.^) are inserted in broad, membranous areas occupying the 

 sides of the meso- and meta-thorax above the epimera and below the scuta of those seg- 

 ments. The hinder pair of wings in the male are distinguished by a sort of pocket, on 

 the upper side, forming a small blister on the rib, knoAvn as the first branch of the median 

 vein, opening by a narrow slit and containing scales and hairs.^ 



The legs show the usual five divisions into the coxa, trochanter, femur, tibia and tar- 

 sus. The first pair, however, are much smaller, and, indeed, functionless, as in all the 

 higher butterflies. They also are different in the two sexes ; the tarsi of the males are 



1 Wcstwood, Newport and other authors have erroneously eral good sections of scales were made, showing their upper- 

 described the patagia as attached to the prothorax, and this and lower membrane, the former beai-ing the rib-like mark- 

 is accordingly often repeated in our text books. Packard, ings. Fig. 6 on pi. 1 shows two of these sections fig. 6 



Guide to the Study of Insects, gives the correct statement. through the middle of the scale, and 6, a, lower down, pass- 



'^ In making sections through the wings at this point, sev- ing through the pedicel. 



