The Genus Hylastes, Er. 127 
stout spines. The palpi are three-jointed, the first joint being as long as the 
second and third joints together. 
Antenne (Fig. 7).—These, as is usual in the Scolytide, are geniculate and 
are divisible into three parts—the scape or shaft adjoining the head, the 
funiculus or whip forming the median portion, and the club or apical 
Deal 
Fig. 7.—The Antenna of H. ater. 
portion. The whip is seven-jointed, the first joint being large and con- 
Spicuous, the second joint smaller, the third joint smallest, while the 
remaining four increase gradually to the seventh which adjoins the club. 
The club is oval, slightly acuminate, and shows three sutures. 
Thorax. (Figs. 8-12.) 
The thorax is divisible into three distinct segments, prothorax, nesothorax 
and metathorax. 
Prothoraz.—This is the most prominent of the three regions. Viewed 
dorsally, it is long and narrow with the sides sub-paralle] and rounded in 
front. Itis markedly longer than broad (Fig.12). It is strongly punctured at 
the sides, less so at the disc, where there is a more or less distinct impuncturate 
median line. This line is very variable, being sometimes reduced to a mere 
patch. It is not raised. No division into separate regions is visible, and, 
except for the puncturation, the dorsal surface of the prothorax is 
featureless. 
Viewed from the side, the prothorax is seen to taper ventrally towards the 
coxz, which are large and prominent. Its puncturation is coarser than that 
of the dorsal surface, except for a small and slightly raised circular area 
above the coxe. 
