44 RHYNCHOPHORA. 
PTEROCOLUS. 
Pterocolus, Schoéuherr, Gen. Cure. i. p. 238 (1833). 
Apotomus, Kirby, Fauna Bor.-Am. iv. p. 205 (1837). 
1. Pterocolus auricollis, sp.n. (Tab. II. fig. 16.) 
Subrotundatus, nigro-cyaneus, prothorace aurato, elytris cyaneis, antennis, tibiis anterioribus tarsisque piceis. 
Long. cum rostro 23 millim. 
Hab. Panama, Bugaba (Champion). 
Antenne with the very loosely articulated club as long as the rest of the joints. 
Head brassy ; rostrum very short, not longer than the head. ‘Thorax of a dark golden 
colour, densely punctate, finely pubescent. Elytra rather closely punctate, and with 
series of punctures placed in very shallow grooves that become quite obsolete behind ; 
about the epipleure with some golden pubescence. Underside of a pallid steel-blue 
colour. Pygidium brassy. The front tibie in greater part rufescent, the middle pair 
rufescent at the extremity. 
2. Pterocolus grossus, sp. n. 
Niger, supra cyaneus, tenuissime pubescens, fortiter sculpturatus. 
Hab. Mexico, Yolotepec, Parada (Sal/é), Acapulco (Hége). 
Rostrum black, shining, longer than the head; antenne with broad club, the first | 
two joints of which are transverse. Thorax much narrowed in front, densely and 
coarsely punctured, the punctuation substrigose longitudinally. Elytra with deep, 
broad grooves, which are coarsely sculptured ; interstices impunctate. 
Only one example has been procured in each locality. These do not exhibit any 
sexual distinctions on the ventral segments, but the individual from Acapulco is 
smaller and has a shorter rostrum; it may be the male, if not it must belong to 
another species. JP. grossus is a little larger than P. auricollis. 
APTEROCOLUS, gen. nov. 
Elytra ad suturam valde abbreviata, segmentis dorsalibus abdominis quinque visibilibus. 
This genus is closely allied to Péerocolus, but has five of the dorsal segments exposed 
instead of three, the posterior coxz very widely separated, though the anterior pair are 
more approximate, and the rostrum furnished with very deep lateral scrobes, which are 
not visible from the front, as the edge of the rostrum projects over them; similar 
scrobes exist really in Péerocolus, but owing to the antenne being inserted nearer to 
the eyes the scrobes are much less conspicuous than in Apterocolus. 
