434 Annals of the Carnegie Museum. 



have been chosen for that purpose. Brunner von Wattenwyl included 

 six species, Giglio-Tos added two others, while Rehn described two 

 more. The material now being studied likewise seems to contain 

 two additional forms which can best be placed in the genus Tetano- 

 rhynchus. 



As stated by Brunner von Wattenwyl the representatives of this 

 genus bear a strong resemblance to those of Cephaloccema Burmeister, 

 and differ in some of its representatives only in the separation of the 

 dorsal and ventral portions of the pronotum by a well-defined, con- 

 tinuous, longitudinal groove on each side. As shown in the descrip- 

 tion of T. gracilis, which follows, even this character is not permanent, 

 for occasional individuals occur, in which there is a complete separation 

 of these parts. This character seems to be one which, to a certain 

 extent at least, belongs more frequently to immature than to mature 

 individuals. There are at hand two nymphs of one of these insects 

 from Puerto Suarez, Bolivia, which in all other characters are Tetano- 

 rhynchus, but in which the separation is as complete as in any Cepha- 

 loccema. 



Additional forms undoubtedly occur over the vast region which 

 seems to be their home. Being entirely apterous and possibly also 

 more or less closely confined to certain host plants, as well as regions 

 determined by climatic conditions and surface configuration, careful 

 collecting and study will no doubt result in a much better knowledge 

 of the family as a whole, and also to the addition of many new forms. 

 The annexed synoptical key will aid the student in the separation of 

 the dozen recognized species of Tetanorhynchus: 



Synopsis of the Species of Tetanorhynchus. 

 A . Rostrum of the vertex of female shorter or at least no longer than the remainder 

 of the head. (The posterior tibiae above on the inner margin with not 

 more than 20 or 21 spines.) 

 b. Rostrum of the vertex of the female much longer than one-half of the re- 

 mainder of the head. Posterior tibiae below on the outer margin 

 spined towards the apex. 

 c. Rostrum of the female with all the carinae prominent, viewed from the 

 front eruciform or cross-shaped. (Posterior tibiae above on the inner 

 margin 10-11 spined. Subgenital plate but little produced.) 



■punctatus Klug. 



cc. Rostrum of the female with the carinae, especially the lower ones, less 



prominent, viewed from the front quadrate or lamellate. 



(Posterior tibiae above on the inner margin variously spined.) 



d. Form graceful, especially in the males. 



