DIASTETHUS. ; 925 
the punctuation denser and very fine on the squamose portions of the surface; prosternal sulcus very 
shallow ; metasternum binodose in front. Femora sharply dentate, the intermediate and posterior pairs 
also with a minute additional tooth on the opposite edge of the shallow sulcus beneath. Intermediate 
tibie armed with a very long spiniform tooth on the outer edge near the apex. 
Length 8, breadth 54 millim. ( 9.) 
Hab. Nicaragua, Chontales (Belt). 
One specimen. Broader and larger than D. violaceus; the prothorax very broad, 
and arcuato-explanate at the sides; the elytra not depressed along the whole length 
of the suture, the strize deeper, those towards the suture less distinctly punctate; the 
metasternum binodose and somewhat protuberant in front; the intermediate tibie 
armed with a long tooth externally. 
This species is nearly allied to the South-American D. tumidus (Boh.), which has 
the metasternum bifurcate in front, &c. It is very like Cylindrocerus smaragdinus and 
azureus, Boh., both of which have a long antennal club. 
2. Diastethus violaceus, sp.n. (Tab. XIII. figg. 2, 2a, ¢.) 
Rhomboidal, convex, shining, violaceous or blue, glabrous above; the prosternum, the sides and anterior 
portion of the metasternum, the ventral segments 1 and 2 (except laterally), and the other segments at 
the sides or apex, thickly clothed with narrow, whitish, striated scales, the rest of the under surface 
almost bare. Rostrum long, thickened and abruptly bent at the base, sparsely punctate, smooth at the 
tip, the antennz inserted at about the basal fifth, the club stout and ovate. Prothorax strongly rounded 
at the sides to the narrow anterior lobe, sparsely punctate, the base obliquely depressed on each side of the 
median lobe. Scutellum very broad, short. Elytra triangular, depressed below the basal margin and 
along the suture ; punctate-striate, the sutural stria deep, the others fine and shallow, the punctures 
oblong in shape and conspicuous throughout, the interstices flat. Beneath with the squamose portions of 
the surface densely, finely punctate, the scattered punctures on the mesosternal side-pieces large and 
foveiform, those on the propleura and metathoracic episterna coarse; prosternal sulcus shallow, the 
anterior coxw widely separated; metasternum flattened, not prominent; ventral segment 1 very broadly 
excavate and 5 depressed down the middle, the depression on 5 limited on each side by a small cluster 
of scales, Femora sulcate and bidentate beneath, the anterior pair sometimes with a single tooth only, 
Tarsal joints 2 and 3 broad. 
Length 5-6, breadth 3-34 millim. (¢-) 
Hab. Muxico (Sallé) ; Nicaracua, Chontales (Janson). 
Three males, the one from Chontales being much larger than the others. The 
violaceous colour, the very broad scutellum, the densely squamose portions of the under 
surface, and the broad tarsi characterize D. violaceus. It is allied to D. politus (Germ.), 
differing from that species in the finer squamosity of the under surface, the scales also 
extending over a portion of the ventral surface. 
3. Diastethus superbus, sp.n. (Tab. XIII. figg. 3, 3a, 3.) 
Oblong-subrhomboidal, finely alutaceous, golden-green, the disc of the prothorax in great part and the outer 
half of the elytra cupreous, the suture of the elytra violaceous, the under surface and legs green or 
pluish-green, the tarsi violaceous, the rostrum of the 2 in great part and the antenne black; glabrous 
above, the under surface and legs clothed with short whitish hairs. Rostrum long, thickened at the 
base, punctate and alutaceous to near the tip in the ¢, longer, smoother, and shining in the 2 ; antennie 
BIOL. CENTR.-AMER., Coleopt., Vol. LV. Pt. 5, November 1907. 2G6G 
