58 HEMIPTERA-HETEROPTERA. 
EUSCHISTUS. 
Euschistus, Dallas, List Hem. i. pp. 193 & 201 (1851) ; Stal, Ofv. Vet.-Ak. Férh. 1867, p. 528. 
Lycipta, Stal, Rio. Hem. ii. p. 58 (1862). | 
About forty species are at present enumerated as belonging to this genus. Its range 
is the Nearctic and Neotropical Regions ; and it exists under very different climatic con- 
ditions. The apex of the head is rounded or emarginate, the central lobe sometimes a 
little longer or a little shorter than the lateral lobes ; the tibie are sulcated ; the lateral 
angles of the pronotum are prominent, sometimes acute and spinous, and sometimes 
rounded as seen in some variable species ; the anterior lateral pronotal margins are gene- 
rally denticulated or crenulated: and this peculiarity was originally one of its distinctive 
characters ; but recently Stal described a species which has the lateral margins of the 
pronotum smooth, thus reducing the value of this portion of the diagnosis, and making 
it of sectional value only. 
A.. Anterior lateral borders of the pronotum denticulated or crenulated. 
1. Euschistus verrucifer. (Tab. V. fig. 14.) 
Padeus verrucifer, Stal, Stett. ent. Zeit. xxiii. p. 101. 64’. 
Euschistus verrucifer, Stal, En. Hem. ii. p. 24. 7°. 
Hab. Mexico 12, 
The specimen figured is in the collection of Dr. Signoret. 
2. Kuschistus tristigmus.. (Tab. V. figg. 20 & 21.). 
Pentatoma tristigma, Say, New Harm. Ind. Dec. 1831; Compl. Writ. i. p. 314. 4; H.-S. Wanz. 
Ins. vii. pp. 95 & 101, fig. 767°. 
Cimex pyrrhocerus, H.-S. Wanz. Ins. vi. p. 71, fig. 638”. 
Euschistus luridus, Dall. List Hem. i. p. 207.17, t. 7. fig. 6°; Glover, Ill. Ins. Ord. Hem. t. 11. fig. 13. 
Euschistus tristigma, Dall. List Hem. 1. p. 207. 18; Glover, Ill. Ins. Ord. Hem. t. ix. fig. 24. 
Euschistus tristigmus, Stal, En. Hem. ii. p. 26. 20*; Uhler, Bull. U.S. Geol. & Geogr. Surv. vol. ii. 
p. 286. 4°. 
Hab. Norvu America’?®*°.—Mextco (Sichel, Mus. Vind. Ces.), Oaxaca (Mus. Berol.) ; 
GUATEMALA, Capetillo, Duefias, San Gerdnimo (Champion). 
The late Prof. Stal first grouped these divergent forms together as constituting one. 
species. ‘This view was afterwards accepted by Prof. Uhler, who studied the varieties 
on the spot, and who remarks :—“ No species thus far discovered in this country (North 
America) exhibits such a wide range of differences in the form of the pronotum. The 
form most common in Maryland has acute and acuminate lateral angles, but longer than 
in others from Pennsylvania, Virginia, Louisiana, and some other parts of the South. 
