254 HACHIRO YUASA 



lateral ocelli, while in the latter, the epicranial arms are very 

 conspicuous, semicircular, and extend to the middle of the mesal 

 margins of the compound eyes and apparently continue cephalad 

 to the lateral margins of the antacoriae. In Mantis (figs. 3, 4), 

 Stenopelmatus (fig. 6), and Melanoplus (fig. 10), the stem is dis- 

 tinct, represented by a parademe in the latter. The stem is 

 i-epresented in Orchelimum (fig. 7) by a longitudinal median fur- 

 row which becomes obsolete near the dorsal margin of the caudo- 

 dorsal median prominence of the epicranium. In Diapheromera 

 (fig. 8) the stem is the long faint line, seen only in treated speci- 

 mens, which bifurcates between the antacoriae. It is obsolete 

 in Tettix (fig. 11) and its position is indicated by a short para- 

 deme on the caudal aspect of the head. In Mantis the epicranial 

 arms are represented by the parademe caudad of the lateral 

 ocelli; they are very short and faint in Diapheromera; obsolete 

 in Orchelimum, although the deep transverse furrow at the 

 cephalic margin of the epicranial prominence may represent them. 

 In Stenopelmatus their position is indicated by the parademes 

 which terminate near the mesal margins of the antacoriae. They 

 are short in Melanoplus and bend caudad between the caudal 

 ends of the compound eyes; obsolete in Tettix, their position is 

 indicated by a short curved parademe between the compound 

 eyes. 



The frontogenal suture (fgs) in Blatta extends laterad for some 

 distance from the lateral end of each pretentorina, then caudad 

 toward the cephalomesal angle of the compound eye, where it 

 merges into ^ a short furrow which originates near the caudo- 

 lateral margin of the antacoria. It is only slightlj^ curved in 

 Mantis and Gryllus, becoming obsolete near the cephalic part 

 of the mesal margin of the compound eye; it is very short in 

 Diapheromera and terminates near the middle of the cephalic 

 margin of the eye; is depressed in Melanoplus and short in Tettix 

 and terminates at the cephalomesal angle of the eye; in Aniso- 

 labis apparently merges into the cephaHc end of each epicranial 

 arm near the antacoria, and is wanting in Orchelimum and Sten- 

 opelmatus. The frontogenal sutures are considered as the ce- 

 phalic portions of the epicranial arms which have been isolated 



