158 RHYNCHOPHORA. 
are broadly depressed down the middle in the male, and the rostrum in this sex is 
more rugose than in the female. 
4. Ambates albovittatus, sp.n. (Tab. IX. figg. 16, 16.0, 3.) 
Elongate, shining, black or nigro-piceous ; the prothorax with a broad vitta on each side, extending forward 
on to the intraocular portion of the head, the elytra with a broad marginal vitta, curving inward towards 
the suture before the apex and extending broadly downward on to the lateral portion of the metasternum, 
and the scutellum, densely clothed with oval yellowish-white scales, the rest of the upper surface rather 
sparsely clothed with brownish, and that of the under surface with whitish, piliform scales. Rostrum 
very stout, strongly arcuate, closely punctate and tricarinate. Prothorax subconical, slightly rounded at 
the sides, nearly as long as broad, closely, finely, rugulosely punctate. Elytra elongate, finely punctate- 
striate, the interstices flat and minutely punctate. Beneath closely punctate ; ventral segments 1 and 
2 broadly depressed down the middle in the g. 
Length 8-93, breadth 3-33 millim. (¢ 2.) 
Hab. Panama, Bugaba (Champion). 
One pair. Very like the more northern 4. heilipoides, but with the marginal 
white stripe of the elytra extending broadly downward on to the lateral portion 
of the metasternum, and not excised on its inner or outer edge, the vestiture of 
the rest of the upper surface brownish. The non-ciliate posterior tibie of the male, 
the unspotted abdomen, and the abbreviated, posteriorly curved marginal stripe of the 
elytra distinguish 4. albovittatus from all the forms of 4. polymorphus. 
5. Ambates leucopleura, sp. n. (Tab. IX. figg. 17, 17a, ¢.) 
Elongate, rather shining, black, the tibie and tarsi reddish in one specimen ; the prothorax and elytra with 
a continuous narrow submarginal vitta, extending forward on to the head and rostrum, and the entire 
under surface, a broad bare space down the middle of the metasternum and abdomen excepted, densely 
clothed with ochreous or yellowish-white scales, the elytra in one specimen with small clusters of 
similarly-coloured scales placed along the striz, the rest of the vestiture of the upper surface very fine, 
fuscous, that of the legs yellowish. Rostrum longer than the head and prothorax, strongly arcuate, 
stout, rugulosely punctate and tricarinate to beyond the middle, sparsely punctured at the tip. Joints 1 
and 2 of the funiculus equal in length. Prothorax almost as long as broad, rounded at the sides 
anteriorly, feebly constricted and much narrowed in front; densely, finely, rugulosely punctate, with 
indications of a smooth median line. FElytra elongate, finely punctate-striate, the interstices closely, 
minutely punctate. Ventral segments with the bare central portion very sparsely punctate, and 1 and 2 
broadly excavate down the middle, in the ¢. Tarsal claws free. 
Length 77-71, breadth 23-24 millim. (d¢.) 
Var. Smaller, the dark vestiture of the upper surface denser and more or less metallic; the elytra more 
finely striate, the interstices flat throughout and densely punctulate. 
Length 44-5, breadth 1§-2 millim. (¢ @.) 
Hab. Costa Rica, Carrillo (Underwood); Panama, Bugaba, Volcan de Chiriqui 
(Champion). 
Eight specimens, two only belonging to the larger form. Closely related to the 
S.-American 4. guadrilineatus (Fabr.), but more shining, the metasternum and 
abdomen with a broad, bare space down the middle, the sides of the body beneath 
