HEXACOLUS. 183 
4, Hexacolus piceus, sp. n. 
Subelongatus, glaber, nitidus, piceus, prothorace haud transverso, antice subtilissime ruguloso ; elytris lineato- 
punctatis, linea suturali vix impressa, interstitiis paullo subtilius uniseriatim punctatis. 
Long. 1°8 millim. 
Mas. Fronte media pilis applicatis fulvis ornata. 
Fem. Fronte glabra. 
Rather elongate, glabrous, shining, piceous or piceous-brown, the head and an apical spot on the prothorax 
black. Front (¢) covered with close-lying fulvous hairs; front (2) convex, glabrous, shining and 
subimpunctate ; antenne fuscous, the base of the scape lighter, club short-oval. Prothorax as long as 
broad, the sides gradually and uniformly rounded from behind the middle to the apex, hind angles 
subrectangular, base truncate, impressed on either side and margined towards the hind angles; disc 
almost uniformly subconvex, obliquely declivous in front, its anterior third subasperate with very fine 
transverse rugosities, hinder part with microscopic scattered punctures, the interspaces closely reticulate. 
Scutellum small, rounded triangular. Llytra a little wider at base than the prothorax, and nearly twice 
as long, their basal borders subtruncate and not margined, the sides parallel to the middle, thence 
obliquely rounded to the apex ; surface lineato-punctate, the sutural stria alone impressed towards the 
base, interstices narrow with a single series of finer but as frequent punctures, declivity convex, shining, 
more finely punctate. Underside shining, subglabrous. 
Hab. Panama, Volcan de Chiriqui (Champion). 
A pair. In structural characters which are not sexual this species agrees with 
H, unipunctatus. 
Group TOMICIDES. 
‘This group is here regarded as the equivalent, so far as the Central-American forms 
are concerned, of the Tomicini of Eichhof’s ‘ Ratio Tomicinorum,’ after the omission 
of the genera Problechilus, Pycnarthrum, and Hexacolus. As is the case with the 
Hylesinides, its constituent species are readily distributed by their structural differences 
into genera; but to arrange these genera into subgroups by a synthetic disposition of 
their characters is by no means easy. 
Two such arrangements, by Leconte and Hichhoff respectively, deserve notice. In 
his ‘Rhynchophora of America north of Mexico,’ the former writer has given an 
excellent account of the tolerably representative genera of that region, drawn up with 
his usual close attention to structural details; his scheme, however, appears to be 
scarcely natural, owing to the excessive use made of the antennal club as the structure 
by the variations of which the subgroups are defined. Thus, while Pityophthorus, 
with which is included Gnathotrichus, and Hypothenemus are put into one subgroup 
with the very distinct Corthylus and Pterocyclon (Monarthrum), Cryphalus, which 
is often regarded as not even distinct from Hypothenemus, is positively relegated to 
the company of Xyleborus and Dryocetes. ‘The club affords excellent characters of a 
kind, but their value requires much controlling by a concomitant use of the other 
structural features. 
The classification, on the other hand, proposed in Eichhoff’s monograph is more 
natural in its grouping, with the limits of which I am disposed to agree, except 
