1913] Anatomy of the Squash Bug. 431 



the Metatarsus (meta), and the terminal segment the ungula 

 (u). This bears divergent claws called unguicula (ua) beneath 

 each of which lies a pulvillus (pu) modified to form a concave 

 adhesive pad (PL LV, f. 3). 



Mesothorax. — The mesothorax is attached to the prothorax 

 by the intersegmental membrane, and the two segments are 

 easily separated, thus uncovering the anterior area of the 

 scutellum and the scutum and prescutum. The covered areas, 

 or the scutum and prescutum, are also called the dorsulum. 



The scutum (sc) is divided longitudinally by a wide median 

 furrow. In the scutum, on either side of the median furrow are 

 two irregular longitudinal impressed lines (d) , which are possibly 

 homologous with the parapsidal furrows of the Hymenoptera. 

 If this be the case, then the area lying between the two last 

 mentioned impressed lines would be the prescutum (psc), 

 while the areas lateral to the lines would be the scutum (PL 

 LVI, f. 10). 



Lying posterior to the scutum and separated from it by a 

 transverse ridge is the scutellum (set), which is triangular in 

 outline and projects posteriorly over the metathorax and the 

 first abdominal segment. On the lateral edge of the scutellum 

 is a ridge called the frenum (fm) (PL LVI, f. 10). 



The postcutellum (psct) of the mesothorax forms the anterior 

 wall of the phragma (phr) situated between the meso and the 

 metathorax, while the prescutum (psc) of the metathorax forms 

 its posterior wall. Both of these sclerites are only slightly 

 visible externally (PL LVI, f. 10). 



The fore wings are characteristic of the suborder Heteroptera 

 being partly membranous and partly coriaceous. Their bases 

 articulate with the mesonotum by means of small chitinous 

 plates called ossicula or axillaries. 



The 'membranous and coriaceous portions of the fore wings 

 are separated by a more or less broken oblique suture called the 

 sutura membranae (s-m). The coriaceous portion is marked 

 off into three areas by two longitudinal sutures (PL LVIII, f. 19). 

 These areas are as follows : the clavus (cl) , which lies next to the 

 mesoscutellum when the wings are in repose; the corium (cr) 

 which lies between the two sutures; and the embolium or costal 

 area (em), which lies beyond the second suture. The first suture 

 or the one which marks off the clavus is called the sutura clavi 

 or anal furrow (s-c) . The suture separating the corium from 



