262 HACHIRO YUASA 



margins of the occipital foramen are considered as belonging to 

 the metatentoria. The fan-shaped plate connected with each 

 pretentorina is a pretentorium. Its cephalic margin is thickened, 

 and its dorsomesal margin is thickened and turned mesad. The 

 expanded caudal parts of the pretentoria converge, fuse on the 

 meson, separate bounding a small opening, and then fuse with 

 each other and the cephalic portion of the corpotentorium. The 

 quadrate plate, the cephalic part of which is arched, is the 1am- 

 inatentorium. The two tendinous projections which extend 

 cephalad from the opening in the tentorium are the oesotendons 

 (ot). The circular opening is the foramen through which the 

 nerve cord passes. The line of fusion of the pretentoria on the 

 meson is indicated by a ventral ridge located cephalad of the 

 opening. The thin, cuticular, triangular plate continuous with 

 each caudolateral margin of the laminatentorium is a supra- 

 tentorium. The apex of the triangle is produced into a thin, 

 delicate, slender extension which is directed laterodorsad toward 

 an antacoria. The point of attachment could not be determined, 

 but it has been stated that it is attached to the caudolateral 

 margin of the antennaria. 



The metatentoria are always distinct and afford excellent land- 

 marks for beginning the study of the tentorium. The corpo- 

 tentorium connects the postgenae and forms the cephalic margin 

 of the occipital foramen. It is usually vertical in position, but 

 in Anisolabis it is a narrow horizontal plate. Each metaten- 

 torium fuses with a postgena on the dorsal side and with a max- 

 illaria on the ventral, and extends as a more or less flaring band 

 a^ong the lateral and caudal margins of the occipital foramen. 

 The flaring inner margins are produced as tendons (figs. 23, 28, 

 and 32). 



The pretentorium is generally fan-shaped or expanded where 

 it is attached to the pretentorina on the ental surface of the fron- 

 togenal suture. Each is directed caudomesad for a short dis- 

 tance, then is twisted, again expanded, extends to the meson, 

 and fuses with the other pretentorium, and forms a more or less 

 distinct laminatentorium. The pretentorium in Mantis is turned 

 caudad and follows the frontogenal suture to its caudal end. The 



