ACANTHOCERUS.—ACANTHOCEPHALA. 117 
Camptischium clavipes, Stal, Hem. Fabr. i. p. 49. 1. 
Stoll, Pun. figs. 98, 287. 
Acanthocerus (Camptischium) clavipes, Stal, En. Hem. i. p. 145.4*; Berg, Hem. Argent. p. 68. 82°. 
Hab. Panama (coll. Dist.).—Cotoms1a 4; Guana ?4, Demerara 1, Cayenne ?; Brazi‘, 
Madeira, river Amazons (coll. Dist.) ; ARGENTINE REPUBLIC ®. 
MACHTIMA. 
Machtima, Amyot § & Serville, Hist. des Hém. p. 215 (1843); Stal, Ofv. Vet-Ak. Forh. 1867, p. 540. 
The lateral margins of the pronotum are entire, not denticulated, and the apical joint 
of the antenne longer than the penultimate. 
Of this Neotropical genus, one Mexican and two other species, received from Brazil 
and Colombia, are all that are at present known. 
1, Machtima mexicana. (Tab. XI. fig. 15.) 
Machtima mezicana, Stal, En. Hem. i. p. 147. 2'. 
Machtima crucigera (h), Walker, Cat. Het. iv. p. 120. 1”. 
Hab. Mexico ! (coll. Dist.)—HonDuras ?. 
This species is very closely allied to VM. crucigera, Fabr. The differences appear to 
be mostly of colour alone; and it is questionable whether it is not a local race of the 
Fabrician species. 
Subfam. ACANT HOCEPHALINAK. 
Placoscelidida, Stal, Ofv. Vet.-Ak. Férh. 1867, p. 535. 
Acanthocephalina, Stal, En. Hem. i. p. 149 (1870). 
This subfamily comprises a group of Neotropical insects which only just, and to a 
small extent, enter the Nearctic Region. Of the nine recorded genera two are found 
in Central America. | 
ACANTHOCEPHALA. 
Acanthocephala, Laporte, Ess. Hém. p. 29 (1882). 
Diactor, p., Burm. Handb. ii. 1, p. 333 (1835). 
Metapodius, Hope, Cat. ii. p. 4 (1842); Dall. List Hem. ii. p. 878 (1852) ; Stal, Ofv. Vet.-Ak. 
Forh. 1867, p. 541. 
Metopodus, Amyot & Serville, Hist. des Hém. p. 192 (1843). 
The largely dilated posterior tibie, and the posterior femora armed above with 
small tubercles and inwardly spined, are salient characters of this genus. Stal thus 
further particularizes it—* Articulis duobus apicalibus rostri ad unum articulo secundo 
longioribus.” The species which form this genus are of an extremely variable character ; 
and many which have been described are doubtless of synonymic value only. However, 
