HEMIPTERA. 351 



TABLE OF GENERA. 



I. Sternum with a keel 1. PLACOSTERNUM. 



II. Sternum unarmed. 



A. Abdomen with a long spine at the 



base 3. PLATACANTHA. 



B. Abdomen unarmed. 



a. Body broad, ovate or oblong; 

 head broad. 



1. Thorax entirely unarmed .... 2. PHYLLOCEPHALA. 



2. Angles of the thorax more or 

 less produced. 



a. Anterior angles of the thorax 

 produced forwards into flat 



processes 4. TETRODA. 



b. Lateral angles of the thorax 

 produced into spines or 

 horns. 



* Lateral angles of the tho- 

 rax produced into long, 

 stout horns, directed for- 

 wards 5. CRESSONA. 



f Lateral angles of the tho- 

 rax produced horizontally. 



a. Head furcate 6. DIPLORHINUS. 



@. Head cleft, but with 

 the inner margins of the 

 lobes contiguous 7- SCHISMATOPS. 



b. Body narrow and elongate ; head 

 pointed in front, with the apex 

 sometimes furcate. 



1. Lateral angles of the thorax 

 prominent or spinous 8. MACRINA. 



2. Thorax unarmed 9. MEGARHYNCHUS. 



Genus 1. PLACOSTERNUM. 



Cimex, p., Fab. Ent. Syst. iv. (1794). 

 Edessa, p., Fab. Syst. R. (1803). 

 Placosternum, Am. $ Serv. Hem. 174 (1843). 



1. PLACOSTERNUM Taurus. 



Cimex taurus, Fab. E. S. iv. 91. 48 (1794). 

 Edessa taurus, Fab. S. R. 145. 1 (1803). 



