FAM. MEMBRACID^ 63 



SuBF. PLATYCOTIN/E Subf. nov. 



TRIBES OF THE SUBF. PLATYCOTIN^ SUBF. NOV. 



I. Uiider wings with four apical cells Potniini Goding. 



II. Under wings ivith three apical cells Platycotini Tribus nov. 



GENERA OF THE TRIBE POTNIINI GODING 



I. Humeral angles produced into long horns Alchisme Kirkaldy. 



II. Huineral aiigles not produced into horns or spines. 



A. Pronotum without dorsal processes Ochropepla Stal. 



B. Proiwtum with dorsal processes or frontal horn 



1. Frontal horn sharp ; sides of pronoium ridged ; posierior process long, 



reaching to tips of iegmina Aconophoroides Fowler. 



2. Frontal horn blunt ; sides of pronoium smooth; posterior process short, not 



reaching beyond end of abdomen Potnia Stal. 



19. Genus ALCHISME Kirkaldy 



Alchisme Kirkaldy, Entom. XXXVII : 279 (1904). 

 Triquetra (preoccupied) Fairmaire, Rev. Memb. 279 (1846). 

 Microschema Stal, Hem. Fabr. II : 37 (1869). 



Characters : Fairmaire erected his old genus Triqueira on the following chaiacters which, of 

 course, still apply : Head large. triangular, slightly rounded at the summit; ocelli equidistant from 

 each other and from the eyes; tegmina slightly notched, free at base but sUghtly covered by pro- 

 notum at extremities; prothorax having the shoulders dilated in long points; posterior process reach- 

 ing tips of tegmina. Of these characters, the long, sharp humeral processes are most satisfactoiy for 

 separating the genus from the other Potniini while the four apical cells of the hind wing distinguish it 

 from the Platycoiini. The insects of this genus are all of large size, among the largest of the Membra- 

 cidae, and are almost without exception greenish in color. They all show, of course, the extremeiy 

 short hind tarsi which are peculiar to the subfamily. 



Type inermis Fairmaire. 



Geographical distribution : 



1. angiistata Fairmaire, Rev. Memb. 282. 11 (1846). Colombia, Ecuador. 



2. apicalis Walker, List Hom. B. M. 5i8. 4 (i85i). Colombia, Panama. 



3. bos Fairmaire, Rev. Memb. 282. 10 (1846). Colombia, Ecuador. 



obtusa Buckton, Mon. Memb. 91 (i9o3). 



4. costaricensis Goding, Journ. N. Y. Ent. Soc. XXXVII : 2. 171 (1929). Costa Rica. 



5. elevata Goding, Amer. Mus. Novit. 10 (1930). Bohvia. 



