170 RHYNCHOPHORA. 
Three specimens. Near A. albiventris, but with the vestiture of the upper surface 
uniformly cinereous and that of the under surface much sparser and finer. Duller 
and more rugose than A. melanops and wanting the black spots on the elytra. The 
antenne are inserted at about the middle of the rostrum. 
33. Ambates cleroides, sp. n. (Tab. X. figg. 12, 12a, ¢.) 
Somewhat fusiform, black, the antenne, the rostrum in part, the basal third or fourth of the elytra, and the 
legs, ferruginous ; the vestiture fine: ochreous and dense between the eyes, white on the apical half of 
the rostrum, legs, and under surface (the ventral segments 3-5 almost bare); the prothorax with the 
anterior half black and the basal half ochreous; the elytra each with an arcuate, transverse fascia at 
about the middle (reaching inward to the first stria) and a common, large, apical spot ochreous, the broad 
intervening space velvety-black, the basal portion rust-red, the basal margin itself whitish and a narrow 
space in front of the curved fascia blackish. Head flattened between the eyes, deeply sunk into the 
prothorax, densely, finely punctate; rostrum strongly arcuate, stout, as long as the head and prothorax, 
closely punctate, carinate down the centre, the antenne inserted at a little beyond the middle, joints 1 
and 2 of the funiculus equal in length. Prothorax broader than long, transversely convex, constricted 
near the apex, the subapical groove sharply-defined beneath, the sides much rounded anteriorly and 
parallel behind; densely, very finely punctate. Elytra moderately long, triangular, flattened on the 
disc ; finely punctate-striate, the interstices flat, densely, rugulosely punctate, 7 and 8 finely costate for 
some distance below the base. Ventral segment 1 very broadly depressed down the middle. Femora 
strongly dentate. 
Length 53-53, breadth 22-23 millim. (<¢.) 
Hab. Panama, David, Bugaba (Champion). 
Five specimens, probably all males. A remarkable insect, having the general 
appearance of a Clerid. The transversely convex prothorax, the flattened, triangular, 
sharply fasciate elytra, and the ochreous frons, give it a very distinct facies from any 
of the other species of Ambates here enumerated. 
PTERACANTHUS. 
Pteracanthus, Schéuherr, Gen. Cure. vii. 2, p. 156 (1843); Lacordaire, Gen. Col. vi. p. 514. 
This genus is based upon a single species from Tropical America, recognizable at a 
glance by the very long projecting humeral and subapical spines of the elytra, the non- 
sulcate prosternum, the contiguous anterior coxe, and the sharply dentate femora. 
Some of the forms here placed under Peridinetus are very like it, but they want the 
elytral spines, and have the prosternum sulcate and the anterior coxe separated by a 
narrow space. 
1. Pteracanthus smidti. (Tab. X. fig. 13, ¢.) 
Rhynchenus smidtii, Fabr. Syst. Eleuth. 11. p. 480 *. 
Pteracanthus smidiii, Boh. in Schonh. Gen. Cure. vii. 2, p. 157°; Lacord. Gen. Col. vi. p. 514°. 
Hab. Panama, Bugaba (Champion).—Soutu America! 2, Cayenne 3. 
We have a single specimen ( ¢ ) of this remarkable insect from Chiriqui. It has the 
first ventral segment depressed down the middle, and the antenne inserted slightly 
behind the middle of the rostrum. 
