110 MODERN CLASSIFICATION OF INSECTS. 
turpentine, when flowing from the wounded fir trees. I remarked, 
however, as a curious circumstance, that all these individuals were 
males. 
In the perfect state many of these insects exhibit various interest- 
ing structural peculiarities ; thus, Cimbex and its allies have clavate 
antenne ; in Hylotoma these organs are apparently composed of a 
single inarticulated joint, two very short basal joints being alone ob- 
servable ; the males of Schizocerus Leach have each of the antennze 
formed of two long equal branches ; those of Cladius have these organs 
slightly branched on one side, whilst they are deeply biramose in 
Lophyrus ; in Lyda the antenne are slender, setaceous, and multiar- 
ticulate ; whilst in Cephus they are thickened at the tips and multiar- 
ticulate. In Tarpa the lower parts of the mouth are considerably 
elongated, so as to form an haustellum. 
The genus Xyela Dalm. (Pinicola Brebisson, Mastigocerus Klug, 
jig. 71.13. Xyela pusilla ¢ ) is one of those anomalous forms which 
so much perplex systematists. The general form of the head and 
body is not materially unlike that of Lophyrus or Lyda, but the 
antenne are singularly constructed, being 13-jointed; the basal joint, 
overlooked by Dalman and Curtis, being small and obconic; the 
second longer; the third short; the fourth forming a long, robust, and 
cylindric stem, equalling or exceeding the nine terminal joints in length, 
which are short and slender; the terminal joint very small in X. 
pusilla, but as large as the preceding in X. Dahlii Adug, a species for 
both sexes of which I am indebted to Dr. Klug. The jaws are robust 
and unevenly toothed (fig. 71. 15.); the under jaws are minute and 
membranous; the inner terminal lobe truncate and setose; the external 
(according to Curtis) being terminated by a smaller one. Hartig, 
however, describes the outer lobe as terminating in two conical lobes. 
The maxillary palpi are greatly elongated and elbowed, so as to re- 
semble a pair of short legs arising from the mouth; they appear to be 
4-jointed, and are so described by Dalman and Curtis; but Hartig 
states that the terminal joint is terminated by three minute fleshy 
joints, preceded by a constriction of the fourth joint. (/ar¢é. pl. 6. f. 30.) 
In X. Dahlii, these organs appear to me to be only 6-jointed, and their 
appearance is represented at fg. 71.17. The labium is represented 
as porrected between the labial palpi by Dalman; and Hartig states it 
to be 3-lobed (fig. 71.18.); but Curtis.has entirely overlooked it. 
The labial palpi are short, and described by Dalman as 3-jointed, and 
