_ EMESA.—GHILIANELLA. 169 
This widely-distributed species is not uncommon in Central America, occurring on 
both the Atlantic and Pacific slopes. The basal third of the abdomen is sometimes 
bright red, the head often has two fulvous vittee behind the transverse groove, and the 
annulation of the legs is not always distinct, the intermediate and hind pairs, however, 
have the knees constantly whitish. The nymph is so different from the fully developed 
form that a description of it is given below, chiefly taken from a broken example from 
Atoyac (where the winged form was also obtained), supplemented by a less mature 
North-American specimen in the British Museum ; this latter has the intermediate and 
hind knees white, as in the developed form. 
Nymph. Eixceedingly slender and elongate, almost glabrous, smooth, somewhat shining; the head ochraceous, 
with two narrowly separated vitte on the anterior portion and the sides before and behind the eyes 
fuscous ; the pro-, meso-, and metanotum and the abdomen ochraceous, with the sides broadly fuscous, 
the mesonotum with two fuscous vitte ; the wing-pads ochraceous externally, fuscous within ; the anterior 
legs ochraceous beneath, fuscous above, the tarsi and the outer half of the tibie broadly annulated with 
pale ochraceous; the intermediate and hind legs brownish, with the knees blackish, the femora towards 
the tip and the tibia near the base biannulated with pale ochraceous ; the antenne brownish, with the tip 
of the basal joint ochraceous. Head without frontal spine, the eyes prominent. Prothorax exceedingly 
elongate, as long as the meso- and metathorax united, the metathorax longer than the mesothorax ; 
the pronotum narrow and cylindrical behind, widening forwards, and swollen at the base, obsoletely 
canaliculate; the pleural margins very minutely denticnlate. Wing-pads extending to a little beyond 
the base of the metanotum. Abdomen very elongate, linear. 
Length 30 millim. 
GHILIANELLA. 
Ghilianella, Spinola, Mem. Soc. Ital. Sci. xxv. p. 142 (1852) ; Dohrn, Linn. Ent. xiv. pp. 218, 236 
(part.) ; Stal, Enum. Hemipt. ii. pp. 125, 126. 
Stal distinguishes this genus from Emesa by the uni-unguiculate anterior tarsal 
claws, the tarsi themselves being long, compressed, and claw-like, and non-articulate 
in both genera; he also uses the granulation of the head and thorax asa distinguishing 
character, but this cannot be depended upon. It may be noted that the mesothorax 
in Ghilianella is prolonged into a long neck in front and abruptly separated from the 
prothorax, whereas in Hmesa the long neck is formed entirely by a backward prolonga- 
tion of the pronotum. ‘The species of Ghilianella, moreover, are constantly apterous, 
without even the rudiments of wing-pads; some of them have the abdomen abruptly 
inflated at or before the apex, the form of dilatation being very dissimilar in the two 
sexes, a fact not even suspected by Dohrn. The anterior tibie are comparatively 
short. ‘lhe anterior femora are armed before the middle with one very long spine, 
between which and the apex is a series of much shorter spines, alternating with still 
shorter spines or teeth. ‘The head has a well-developed frontal spine. One of the 
South-American species of Ghilianella (G. filiventris, Spin.) was described by Fabricius 
as the larva of an Emesa (EL. precatoria, Fabr.). 
The Central-American species may be separated thus :— 
BIOL. CENTR.-AMER., Rhynch., Vol. II., October 1898. 22 
