348 The Philippine Journal of Science 1923 



described as with "appendix absent," shows on a mounted spec- 

 imen a perfectly distinct but very narrow appendix. 



If a specimen of a typical Tettigoniella be examined, it will 

 be noted that the frontal suture passes on to the crown and 

 caudad to near the position of the ocelli. Most of the crown 

 is, therefore, merely an inflated and highly specialized "front," 

 in the morphological application of the term. In fact, in 

 Tettigoniella, we commonly find the oblique stripes, so charac- 

 teristic of the front in many jassoid insects, carried far over 

 on to the crown. The actual vertex in true tettigoniellids, there- 

 fore, even in many forms with greatly produced heads, is very 

 short, but with the ocelli actually near its fore border, the 

 production pertaining entirely to the front, as is commonly the 

 case in the Cercopidae— a family that shows many close relation- 

 ships with the Tettigoniellidae sens. str. In this case the actual 

 basal margin of the front passes across the crown often nearer 

 its base than its apex. In some groups the morphological 

 vertex itself is produced, carrying forward the ocelli, which 

 may thus even come to lie on the face, but still in the same 

 relation to the morphological "front." It thus results that the 

 use of the word "vertex" as equivalent to "crown of head" is 

 entirely erroneous in many cases. The word "vertex" as it 

 occurs in descriptive literature relating to Tettigoniellidse, 

 Bythoscopidae, and some other groups should be replaced by 



In some groups the actual upper margin of front and the 

 anterior margin of true vertex adjoin along the anterior margin 

 of the dorsum of head, and in this case the use of the word 

 "vertex," for the entire disk of the crown within the lateral 

 sutures, is correct. In this case the sutures may be clearly 

 marked or entirely obsolete, but the ocelli will usually be found 

 on the anterior margin or immediately above or below it If 

 the sutures are clearly marked (as in nearly all of the genera 

 m this group) they may be carinately raised, the carina bounding 

 upper margin of front and anterior margin of vertex, often 

 entirely distinct and separate. In the latter case the upper 

 carina may be the stronger, causing the vertex to overhang and 

 extend beyond the front, as in Stenocotis, Koebelia, etc ; or quite 

 the reverse may be the case, as in Euacanthus, many of the 

 Pythamidae, and notably in Balbillus, but there is every grada- 

 tion m this character. In the groups under discussion the two 

 carina- diverge laterally in all of their relative locations de- 

 scribed above, the ocelli being commonly placed between them, 



