l8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 56 



2. Processus pteralis thoracis II (Processus postalaris) (pi. 2, 

 figs. 3, 4; pi. 8, figs. 23, 24; pi. 9, fig. 25, ptil). 



Described above with the scuttim. 



3. Processus pteralis thoracis III (pi. 2, figs. 3, 4 ; pi. 9, fig. 26 ; 

 pi. 10, figs. 27, 28, /j^///) . This process is the prae-epaulet of Strauss- 

 Diirkheim (1828). It arises at the episternum, narrows to a thin 

 band that suddenly broadens distally to a semi-circular piece, and is 

 then drawn out into a delicate band which passes into the mem- 

 brane (see pi. 9, fig. 26) inserted upon the processus pteralis alse 3 

 below the pterale B (pi. 9, fig. 26, pt^). 



4. Processus pteralis thoracis IV (pi. 2, figs. 3, 4; pi. 9, fig. 26; 

 pi. 10, figs. 27, 28, ptIV). This process is the "great ampulla" of 

 Lowne. According to its function and form it may be designated 

 as stroma (cushion) . It is a protruding cushion-shaped piece, united 

 with the episternum by means of a broad band, and situated in the 

 axillary cavity of the thorax. Between the distal end of this piece 

 and the head of the processus pteralis thoracis III there is a tri- 

 angular stay (pi. 9, fig. 26; pi. 10, figs. 27, 28, v). 



5. Processus pteralis thoracis V (pi. 4A, fig. 11; pi. 9, fig. 26; 

 pi. 10, figs. 27, 28, ptV). Four pieces combine to make up this 

 process: the episternum, the parepisternum, the stroma and the 

 episternal border. Three strongly chitinized bands arise from the 

 episternum. These finally unite with the episternal border to form 

 a strong chitinous bar which bears at the end the process. The 

 process itself appears as an inflation. It bears, proximally from the 

 stroma, three small spines and distally one larger one. The entire 

 process somewhat resembles a comb with a handle. 



6. Processus pteralis thoracis VI (pi. 8, fig. 24; pi. 9, fig. 26; 

 pi. II, fig. 29; ptVI). This process arises from the crest that runs 

 along the " lateral plate of the postscutelluni " (Lowne) and is 

 joined to the squama. It is a short, distally thickened, chitinous 

 piece, which shows a saddle-like depression that corresponds with a 

 similar saddle surface in the processus pteralis alse 4 (pi. 11, fig. 

 29, pt4) . 



B. THE INTERMEDIATE PARTS (pTERALIa) 



This group consists of three pieces: 



I. Pterale A (pi. 3, fig. 8; pi. 4A, fig. 9; P^- 8, figs. 23, 24; pi. 9, 

 fig. 25 ; ptA). This pterale is the " dens " of Lowne. It bears four 

 large protuberances, two shorter proximally, and two longer distally 

 directed ones. One of the proximal ones extends into the interior 



