HEAD, MOUTH-PARTS, ORTHOPTERA EUPLEXOPTERA 265 



cockroach can be identified. The acia is generally absent, al- 

 though the digit-like cuticular projection (ac) in Mantis (figs. 

 74, 75, and 76) may represent it. The base of the rectotendon is 

 more or less distinctly chitinized and forms, in many cases, a 

 sclerite-like area, the rectacuta (re) of the ambipharynx. The 

 dentes are always present, but are not differentiable into proxa- 

 dentes (pd) and distadentes (dd) except in Anisolabis (figs. 86 

 and 87). The dentes and mola cannot be distinguished in Diaph- 

 eromera (figs. 80 and 81). 



The maxillae (mx) in Blatta (figs. 97 and 100) are typically 

 orthopterous in structure and each consists of a cardo, stipes, 

 galea, lacinea, palpifer, and maxillary palpus. The cardo (ca) 

 consists of two segments (fig. 98), the subcardo (sa) and ala- 

 cardo (al). The parartis is dorsal in position and bifurcate, the 

 exparartis (ey) is a combination of a condyle and acetabulum. 

 The entoparartis (en) is triangular, prominent, and bears the 

 small premaxatendon (pmt) near its distal end. The alacardo 

 is much smaller than the subcardo and attached obliquely to the 

 lateroventral margin of the latter. The suture between these 

 segments is distinct on the ventral aspect and forms a para- 

 deme. The exparartis articulates with the paracoila and the 

 entoparartis is inserted near the paracoila dorso entad of the 

 mesal margin of the head. The stipes (s) is large, distinctly 

 chitinized on the ventral aspect, and, excepting a triangular area, 

 is largely membranous on the dorsal aspect. It articulates with 

 the alacardo at the caudolateral angle of the latter and is separated 

 from it by a distinct suture. The caudomesal angle of the stipes 

 on the ventral aspect articulates with the laterocephalic angle of 

 the subcardo. Thus the stipes has two points of articulation 

 with the cardo, one on the subcardo and the other on the alacardo. 

 The narrow longitudinal sclerite attached to the mesal margin of 

 the stipes on the ventral aspect is the subgalea (sg). The suture 

 between them is modified into a distinct parademe. On the ven- 

 tral aspect the cephalic margin of the subcardo and the mesal mar- 

 gins of subgalea, and of the stipes, cephalad of the subgalea, are 

 continuous with the labacoria (Ic), while the cephalic and mesal 

 margins of the cardo and stipes, respectively, are continuous on 



