ARILUS.—ACHOLLA. 289 
3. Arilus depressicollis. (Tab. XVII. fige. 25, 25a, 2.) 
Prionotus depressicollis, Stal, Ofv. Vet.-Ak. Férh 1859, p. 196 (9)1; Stett. ent. Zeit. 1862, 
p. 446°; Enum. Hemipt. ii. p. 72°. 
Hab. Mexico ?* (Mus. Berol.1), Mescala in Guerrero (H. H. Smith). 
Of this species we have received a single specimen from Western Mexico; it is a 
female, like the type. A. depressicollis is closely allied to A. cristatus, but it has the 
posterior lobe of the pronotum feebly convex on the disc, with the crest very little 
raised and set with about eight tubercles, and the spines at the base are less divergent ; 
the margins of the abdomen are feebly sinuate. 
ca 
STHIENERA. 
Sthienera, Spinola, Essai sur les Hémipt. p. 117 (1837) ; Stal, Ofv. Vet.-Ak. Férh. 1859, p. 196. 
Piezopleura, Amyot et Serville, Hist. Nat. Ins. Hémipt. p. 362 (1843). 
Harpactor, Stal, Hemipt. Afric. 11. p. 47; Enum. Hemipt. ii. pp. 68, 72 (nec Laporte). 
Erbessus, Stal, Enum. Hemipt. ii. p. 73. 
A Tropical-American genus including six described species, one of which has been 
recorded by Stal from Mexico. It differs from all the other Reduviids from our region 
in having the anterior tibie toothed near the apex beneath. 
1. Sthienera rhombea. (Tab. XVII. fig. 26, 2.) 
Arilus (Piezopleura) rhombeus, Erichs. in Schomburgk’s Reisen in Brit. Guiana, iii. p. 614°. 
Harpactor rhombeus, Stal, Enum. Hemipt. ii. p. 73°. 
Hab. Mexico (Boucard, in Mus Holm. ?).—Gutana ! 2. 
Dr. Aurivillius has lent me the Mexican specimen of this species in the Stockholm 
Museum, and from this our figure is taken. 
ACHOLLA. 
Acholla, Stal, Stett. ent. Zeit. 1862, p. 445, nota; Hemipt. Afr. ni. p. 47; Enum. Hemipt. ii. 
pp. 67, 72. 
Ascra, Stal, Stett. ent. Zeit. 1862, p. 445. 
An American genus including three very closely allied species, ranging from the 
United States to Guatemala. It differs trom Simea in having the anterior femora 
unarmed at the apex above. 
The Central-American forms may be separated thus :— 
Lateral angles of the pronotum obtuse; the ante-ocular portion of the head and 
the anterior lobe of the pronotum with prominent conical tubercles . . . ampliata, Stal. 
Lateral angles of the pronotum rather sharp ; the ante-ocular portion of the head 
and the anterior lobe of the pronotum slightly tuberculate . . . . . . ¢tabida, Stal. 
BIOL, CENTR.-AMER., Rhynch., Vol. II., December 1899. 37 
