488 
ZOOLOGICAL LITEKATUKE. 
1. Thorax much compressed and elevated, very high, and usually pro- 
duced into a horn in front 2. Enchophyllum (A. & S.y, 
2. Back of thorax at least tiicarinate, middle keel sometimes elevated 
and foliaceous. 
a. Back of thorax highly keeled in middle, armed with a compressed 
horn in front, or projecting in a compressed angle. 
• Thorax with some abbreviated keels on the part turned forwards. 
3. Enchenopa (A. 
t Thorax not keeled in front ; head longer than its width between 
the eyes 4. Tritropidia, g. n. 
{Membr. galeata, Oliv., and M. nimhatUy Fab.) 
b. Back of thorax convex and unarmed, or projecting in an angle or 
process which is not compressed. 
6. Tropidoscyta, g. n.® 
B. Body slender j thorax low, back acutely keeled in the middle, with a 
long, thick, subcompressed porrect process in front ; posterior process 
long, passing apex of tegmina .... G. ^Echmophora, g. n. 
{Memhr. elephas, Stal.) 
Stal (/. c. pp. 47-49) tabulates the genera of Centrotida re- 
presented in America as follows : — 
I. Thorax giving off a posterior process extending beyond scutellum. 
A. Clavus not at all or slightly narrowed towards the apex, not gradually 
acuminate (^Centrotida vera). 
1. Anterior margin of thorax straight or very broadly sinuate. 
a. Wings with four apical cells j scutellum bidentate or emarginate 
at apex. 
* Outer vein of clavus long, united with the commissure at a greater 
or less distance beyond middle of clavus ; thoracic process long. 
a. Outer discoidal cell of corium sty late or subtriangular, not 
truncated at base. 
a. Head very broad 1. Monobelus (Stal).* * 
j3. dlead narrower than thorax between lateral angles. 
2. Boocerus (StSl). 
b. Outer discoidal cell of corium truncate at base, sessile. 
a. Thoracic process entirely slender, keeled above, curved an- 
teriorly 3. Acantiiophyes (Stal). 
(Centr. capra. Fab.) 
* Subgenera (Membr. fasciata, Fab.), Enchophylluniy and Tro- 
pidocera (Membr. ensata and lanceolatay Fab.). 
^ Subgenera Enchenopa (M. gladius and hastata, Fab.) and Campylenchia 
(M. curvata, Fab.). 
* Species tabulated pp. 45, 46: — C. gibbosa (Be G.), M. poecila (Germ.), 
T. pallidipennts (StSl), T. comatida (StSl), M. torva (Germ.), M. carbonaria 
(Germ.), M. abbreviata (Fab.), and T, gibbera (Stul). 
* The species of this genus are tabulated by Slal {/. c. pp. 39, 60), and are 
Centr. fasciatua (Fab.), nusutm (StSl), obtusiceps (Stul), ilavidus (Fairm,), and 
lateralis (St&l), 
