THE CANADIAN ENTOMOLOGIST 215 



In comparing the antennae of the Grylloblattids with those of 

 the typical Blattids (e. g., the antennae of Periplaneta americana 

 Linn) we find no such close correspondence in the number of seg- 

 ments, since the typical Blattid antenna is composed of consider- 

 ably over a hundred more segments than are present in the antenna 

 of GryJlohlatta. Furthermore, the segments of a Blattid's antenna 

 are of a very different type from those of a Grylloblattid's antenna, 

 the smaller proximal antennal segments being more annular in 

 outline in the Blattids. In the antennae of the Embiids and 

 Grylloblattids, on the other hand, there is not only a remarkable 

 correspondence in the number of segments composing the antennae, 

 but the similarity extends even to the relative size and the outline 

 of the antennal segments themselves. 



In both Emhia (Fig. 9, 1) and Gryllohlatta (Fig. 9, 2) the scape 

 (Seg. I) is much larger than the pedicel (Seg. II). Furthermore, 

 the pedicel (Seg. II) is of about the same width as the postpedicel 

 (Seg. Ill), but is shorter than the postpedicel (Seg. Ill) in both 

 Emhia (l) and Gryllohlatta (2). In both insects, the post- 

 pedicel (^Seg. Ill) is longer than the succeeding two segments. 

 (Segs. IV and V) which are somewhat annular, or broader than 

 long, in outline. The sixth segment (Seg. VI) is slightly longer 

 than the two preceding it, in both Emhia and Gryllohlatta, while 

 here is a slight increase in length in the seventh segment in both 

 insects. The segments from this point on, gradually become 

 longer, slenderer, and more clyindrical in both insects, and the 

 correspondence, even to the minutest details, is so striking, that 

 even the veriest tyro could not fail to perceive the remarkable 

 similarity in the antennae of these two insects. On the other hand, 

 one has but to glance at the antennae of a typical Blattid, to con- 

 vince himself that the segments of its "whip-lash" antenna are 

 of a very different type from those of Gryllohlatta; and if any con- 

 clusions are to be drawn from a comparative study of the antennae, 

 they would clearly point to a remarkably close relationship be- 

 tween the Grylloblattids and Embiids, and a much more distant 

 relationship to the Blattids.. 



It might be mentioned in passing, that the antennae are 

 situated nearer to the base of the mandibles, and below the eyes, 

 in Embiids and Grylloblattids; while in the typical Blattids, the 



