RHYSSOMATUS.—CONOTRACHELUS. 399 
One specimen. The conical, finely punctured prothorax, the coarsely seriate-punctate 
elytra, with the interstices flat to near the apex, the widely separated anterior coxe, 
the simple tibiw, and the almost glabrous, shining surface, separate R. nitidus from 
all the other Central-American species, the preceding excepted, which also has the 
antenne inserted near the base of the rostrum. 
CONOTRACHELUS. 
Conotrachelus, Schéuherr, Gen. Cure. iv. p- 892 (1837) ; vii. 2, p. 15; Lacordaire, Gen. Col. vii. 
p- 54; Leconte, Proc. Am. Phil. Soc. xv. p. 225. 
Cyphorhynchus, Schonherr, Gen. Col. iv. p. 458. 
Edesius, Pascoe, Ann. & Mag. Nat. Hist. (5) vii. p. 805 (1881). - 
An American genus including innumerable species, about 200 having been described, 
and nearly as many * are now known from our region, whence eight only have previously 
been recorded. It is chiefly recognizable by the open rostral canal, the prominent 
ocular lobes to the prothorax, and the toothed or appendiculate, divergent, tarsal claws. 
The alternate elytral interstices are usually costate, and the dorsal ridges are often 
interrupted and separated into two or more lamelliform prominences, the median one 
on the third interstice being sometimes very conspicuous. ‘The species with a deeply 
excavate mesosternum, belonging to the Stirps 2 of Schénherr’s arrangement (=Sect. E 
of the Table given below), might be excluded, but they are connected with the rest by 
the intermediate forms here placed under Sections C and D, The character used by 
him for his Manipulus I. of Stirps 1 was perhaps taken from female specimens only. 
C. lobatus, C. scoparius, and others have the posterior tibie peculiarly formed in the male. 
C. rectirostris and its allies, as well as C. incanus, &c., have the rostrum longer, smoother, 
and more slender in the female than in the male, and the antenne inserted much 
further from the apex ; but this difference becomes less marked and finally disappears 
as the rostrum becomes shorter and stouter. C. nodifer and C. elongatus (species very 
like the South-American C. leucostictus, Boh.) have a peculiar facies, owing to their 
oblong shape and the elevations on the outer elytral interstices being reduced to 
scattered tubercles. Cyphorhynchus was based upon a few species with the rostrum 
short, and gibbous at the base; and Edesivs upon an insect with very widely separated 
intermediate coxa, a concave mesosternum, and densely squamose upper surface. 
C. nenuphar, Herbst, and various other North-American Conotracheli are said to be 
very destructive to stone-fruits, such as the plum, apricot, &c. 
The following Table will assist in the identification of the Central-American forms; 
but it must not be relied upon altogether, as the two sexes of some of them are not 
known in every case, the mesosternal and other characters gradually merge one into 
the other, and the elytral coste sometimes vary in development in the same species. 
It is probable that some of those from Panama treated as new will ultimately prove to 
* Several are left undetermined for want of sufficient material, 
2XX 2 
