2 PROCEEDINGS OF THE NATIONAL MUSEUM vol.71 



GENERAL STRUCTURE 



An insect of the genus Podalonia is, as a rule at least, under an 

 inch in length. In most cases the body is rather slender and the 

 legs long. The head is quite large, rounded from the front, rather 

 transverse oblong with rounded corners, viewed from above, and 

 quite a portion of it is taken up by the large, compound eyes. 

 Between these the surface is quite flat or even depressed above the 

 antennal articulations, but below these the clypeus in the females 

 may be strongly swollen centrally. The cheeks behind the compound 

 eyes may be quite thick above, contributing largely to the oblong 

 outline, but below this they may narrow quickly or slowly. 



The pro thorax, for convenience, may be divided, above and from the 

 side, into the neck, the rather slender portion to which, at its front 

 end, the head is joined; and the collar. Behind the neck the seg- 

 ment widens and rises more or less abruptly till about as high as the 

 mesonotum ; it then rounds backward, then downward somewhat to 

 articulate with the front margin of the mesonotum. At the sides, 

 the segment also widens somewhat and articulates with the front cor- 

 ners of the mesonotum. It is this elevated region above and its sides, 

 just described, to which the term collar is here applied. At the side, 

 close to the front corner of the mesonotum, is a backward extension 

 of the prothorax nearly circular in outline, slightly swollen so that it 

 somewhat resembles a tegula, and fringed behind with a thick row 

 of short, fine hairs. This projection, here called the prothoracic lobe, 

 lies over a somewhat depressed area of the mesopleuron, concealing 

 a spiracle there. 



The other portions of the thorax call for little in the way of 

 description. Posterior and dorsal to the thorax proper, however, 

 and so compactly joined to it as to form a part of the thoracic mass, 

 is the propodeum or first true abdominal segment, which requires 

 consideration. The dorsal portion of this segment appears to articu- 

 late with the hind margin of the postscutellum by a transverse suture. 

 About at the point where the plate begins to bend sharply downward 

 to form the sides of the body, its structure changes in appearance, 

 marking out lateral limits to the dorsal portion. These lines run 

 backward just above the spiracle located on the side, sometimes 

 bending inward slightly around the dorsal margin of the spiracle, 

 then bending laterally more or less before curving inward to form a 

 pointed tip to this area. The outline of the dorsal area thus limited 

 is quite like a shield and is here spoken of as the propodeal disk or 

 shield. Its surface varies in different species and to some extent in 

 different individuals of the same species but, in general, shows punc- 

 tures and ridges. In their simplest condition the ridges tend to be 

 transverse anteriorly, then more oblique, running back and out from 



