350. HEMIPTERA-HETEROPTERA. 
defined and often more or less ocellated. The pronotum is subparallel at the sides in 
front; the lateral angles are foliaceous, very distinctly crenate in front and behind, and 
transverse or subtransverse along their anterior edge. A fresh specimen from San Feliz 
is figured ; also the underside of a male (Tab. XX. fig. 20), to show the asymmetry of 
the genital segments in this sex. 
Subfam. MONONY CHIN. 
Galgulide, subfam. Mononychina, Stal. 
MONONYX. 
Mononyx, Laporte, Essai Class. Hémipt. in Guérin’s Mag. Zool. 1832, pp. 15, 16; Burmeister, 
Handb. der Ent. ii. 1, p. 201 (1835); Amyot et Serville, Hist. Nat. Ins. Hémipt. p. 425; 
Fieber, Gen. Hydroc. p. 12, t. 14; Stal, Berl. ent. Zeitschr. vii. p. 405; Enum. Hemipt. v. 
p- 138 (nec Brullé) ; Montandon, Bull. Soc. Bucarest, viii. p. 392 (1899). 
? Nerthra, Say, Descr. New Spec. Heteropt. Hemipt. N. Am. (New Harmony, Dec. 1831) ; 
Complete Writings, i. p. 364. 
This peculiar genus includes seventeen described species, seven of which are American, 
four occurring within our limits. In the imaginal form the short anterior tarsi* are 
furnished with a simple strong claw only, the true basal joint being completely fused 
with the tibia, but in the nymph (as in the Australian genus Matinus, Stal) two long 
claws are present. The terminal genital ventral segments of the male, as in Gelastocoris 
(Galgulus), are asymmetric. The antenne are 4-jointed+; the third joint is narrow, 
barely one-third the length of the fourth, and almost connate with it. ‘These insects 
live in muddy places on the banks of ponds and streams, and are usually coated with 
an earthy incrustation, which cannot be easily removed. 
a. Anterior femora widest towards the base. 
1. Mononyx amplicollis. (Tab. XX. fig. 26, 3.) 
Mononyzx amplicollis, Stal, Ofv. Vet.-Ak. Forh. 1854, p. 239'*; Berl. ent. Zeitschr. vii. p. 406 *; 
Enum. Hemipt. v. p. 188°; Mont. Bull. Soc. Bucarest, viii. pp. 395, 400 *. 
Hab. Costa Rica (Van Patten), El Coronel (Biolley, in coll. Montandon *).— 
CotomBia 34, Antioquia!?; VENEZUELA? 4. 
Of this species, which is easily distinguishable by the very broad pronotum, we have 
a single male from Costa Rica. The basal half of the anterior femora, except on their 
posterior edge, and the anterior trochanters are ochreous, as noticed by Stal. 
* Not the posterior pair, as stated by Laporte. 
“+ Three-jointed according to Laporte, four-jointed according to Herrich-Schiiffer. In our fig. 22 a the basal 
joint (as drawn) is partly hidden within the antennal cavity. 
