1918] Crampton — Study of Terga and Wing Bases 7 



position, since in the Embiids (Fig. 3), the alar ossicle "np" evi- 

 dently is a portion of the notum which is not yet completely de- 

 tached, while in the Plecoptera (Fig. 1, "np") it likewise extends 

 for some distance closely applied to the lateral margin of the notum. 

 The only winged Embiid which I have for examination is the male 

 of Embia major shown in Fig. 3, but it is very probable that other 

 Embiids will exhibit a type of alar ossicle similar to the elongate 

 " notopterale " "np" of the Plecoptera (Fig. 1), and even in the 

 Embiid shown in Fig. 3, the alar ossicle "np" is much longer than 

 the homologous sclerites "np" of Figs. 2 and 4. 



In the metathorax of both Dermaptera and Coleoptera (Figs. 2 

 and 4) the sclerite "np" is very similar in outline, and in position, 

 being situated much further forward than in the Embiids and 

 Plecoptera (Figs. 1 and 3), and it is not so elongate as in the Em- 

 biids and Plecoptera, as was mentioned above. In the mesothorax 

 of the Dermaptera (Fig. 4), this plate "np2" has become broken 

 up into two parts, the anterior one of which is bent abruptly down- 

 ward. This has resulted in the incorrect homologizing of the parts 

 of this plate in the mesothorax of the Dermaptera, by some investi- 

 gators, but the two parts of the mesothoracic plate "np2" of Fig. 4 

 are clearly homologous with the single metathoracic plate "nps" 

 of the same insect. 



SnodgTass, 1908-1909, refers to the mesothoracic plate "tg" 

 (Fig. 4) of the Dermaptera, as "a small rod in wing base," appar- 

 ently not realizing its true nature; but Pantel, 1917, correctly 

 refers to it as the tegula. While the tegula "tg" is well developed 

 in both meso- and metathorax in the Embiids and Plecoptera (Figs. 

 1 and 3), I do not think that it is developed in the metathorax of 

 the Coleoptera and Dermaptera, unless the region designated as 

 "t" in the metathorax of the Dermapteron shown in Fig. 4 repre- 

 sents the tegula. Pantel, 1917, refers to the region "ptg" in the 

 metathorax of the Dermapteron shown in Fig. 4, as the metatho- 

 racic tegula, but this region seems to correspond to the so called 

 parategula of Hymenoptera and Diptera (shown in Fig. 4 "ptg" 

 of the wing base of a Dipteron, by Crampton, 1914b). 



Pantel, 1917, considers the metathoracic sclerite "sus" of the 

 Dermaptera (Fig. 4) as one of the pteralia, or articulatory ossicles 

 at the base of the wing. As far as I can judge, however, the region 

 "su" of Figs. 1, 2, 3, and 4, is merely an antero-lateral marginal 



