228 Journal New York Entomological Society, ['^'o'- xxv. 



eighth segment. In the Phasmid Tiincma, the dorsal and ventral 

 valves of the ovipositor (fig. 12, " d" and "v") have a more or less 

 clearly demarked basal "segment" {"h" of fig. 12) and resemble 

 those of the more primitive Blattids (fig. 5) in this respect. Traces 

 of this basal portion of the valvar occur in many other forms as well 

 (figs. 7, 6, etc.), and in certain of the Orthoptera (fig. 10) a more or 

 less vertical basal sclerite labeled "/''■' also occurs. In the Orthopteron 

 shown in fig. 10, this sclerite articulates with a narrow " lora "-like 

 sclerite labeled '' I " which furnishes a firmer support for the move- 

 ments of the ovipositor than the membranous region through which it 

 extends, would give. In the more primitive Phasmids (fig. 12) the 

 posterior region " s" of the eighth ventral segment does not project 

 posteriorly to any great extent, as is true of many other representa- 

 tives of this superorder. In certain Phasmids, however, this portion 

 of the eighth ventral segment projects backward for a considerable 

 distance and forms a sheath for the ovipositor, thus resembling quite 

 closely the condition found in the Mantids (although this portion of 

 the eighth segment is not shown in the ]\Iantid depicted in fig. 7). 

 The tenth abdominal segment is moderately well developed in this 

 group, and the so-called suranal plate ("11" of figs. 6, 10, and 12) 

 projects backward, instead of downward as in the preceding group. 

 The region in question certainly appears more like merely a demarked 

 portion of the tenth segment; but provisionally, at least, the generally 

 accepted interpretation of it as the suranal plate (or suranale) has 

 been adopted in the present paper. The cerci are usually one-seg- 

 mented in this group, but in Grylloblatta (fig. i), they are composed 

 of cylindrical segments similar to those of certain Plecoptera (fig. 

 11). The pericercal organs occurring in rings about the segments 

 of the cerci of the Grylloblattids (fig. i, "0") are apparently sense 

 organs, and their arrangement is quite different from the usual one, 

 in this respect. The cerci of such Gryllids as GUcanthus (fig. 10, 

 " c"), although but one-segmented, are longer than the ovipositor, 

 and suggest a rather close relationship to Grylloblatta (fig. i). 



The superorder Pandictyoptera (composed of the Isopterous, 

 Blattoid, and Mantoid insects) was possibly originally an ovipositor- 

 bearing one, although many of the roaches have lost the ovipositor, 

 and the Isoptera probably neVer developed one. Although it is not 

 shown in the accompanying figures, the ventral portion of the ter- 



