FAM. MEMBRACID^ 



99 



closely related genera Anchistrotus and Omolon by the ridges on the sides of the pronotum. Other 

 generic characters as indicated by Stal are : 



« Alis tegminibus dimidiis longioribus. Processu postico ihoracis marginem interiorem 

 clavi vel hujus venam longitudinalem tangente ; tegminibus totis vel fere totis liberis. Corio 

 areola discoidali unica instructo, ante medium inter venas longiludinales secundam et tertiam, 

 basin versus in unam conjunctas, venula transversa destituto. Thorace tricarinato, praster 

 carinam mediam percurrentum carinas duabus, pone oculos incipientibus, ad vel ultra medium 

 dorsi extensis, instructo; ceteris ut in Combophora. » 



These are the characters which we have used in constructing our key to the genera of the tribe 

 and in determining the species used as our Plate Figure. 



Type laporti Germar. 



Geographical distpibution : Known only from the type species from South America. 

 I. laporti Germar, Rev. Silb. III : 253. 2 (i835). — Pl, 5, fig. 5 6. Brazil. 



carinata Guerin, Icon. Reg. Anim 7 (i838). 



66. Genus OMOLON WALKER 



Omolon Walker, Journ. Ent. I : 3i5 (1862). 



Characters : We have never seen a representative of this genus but it has been recognized by 

 Butler and by Goding who indicate that the genus is to be identified by the subquadrate head. Except 

 for this character it would seem that the insects of this genus are in no way different from those of the 

 genus Anchistrotus. Butler considered Heliodore a synonym of Omolon but apparently did not note 

 either the shape of the head or the lateral carinas in his diagnosis. We cannot figure this genus since 

 we have no specimen of aiiy of the three species and there is no published figure of any of them in the 

 literature of the family. 



Type tridens Walker. 



Geographical distribution : The genus is known only from three species, all described by 

 Walker, and all from Brazil, as follows : 



1. iiicongrua Walker, List Hom. B. M. Suppl. 340 (i858). Brazil. 



2. tridens Walker, Journ. Ent. I : 3i6 (1862). Brazil. 



3. varius Walker, Journ. Ent I : 3i6 (1862). Brazil. 



67. Genus ANCHISTROTUS BUCKTON 



Anchistrotus Buckton, Mon. Memb. 147 (1903). 

 Combophora ipreoccupied) Germar, Rev. Silb. I : 177 (i833). 



Characters : A remarkable genus identified at once by the greatly swollen globular pronotum. 

 The insects are rather brightly colored, mostly of large size, and conspicuous in both structure and 

 markings. Head triangular, eyes ovate and i^rominent; ocelli large, nearer to each other than to the 

 eyes and situated about on a line drawn through centers of eyes. Pronotum swollen into an enormous 

 hoUovv globe and so weakly attached to the body that it is difficult to collect the specimens without 

 detaching it. This bulbous expansion of the pronotum is generally armed with spines, particulaily on 



