TRACHEATA 
311 
brown colour. In external appearance it is very like its larger 
subtropical congener Scolopendra. 
The head bears the multiarticulate antennae, 
with about forty segments, and just behind their 
insertion, the eyes, which are composed of 
twenty-five to forty single eyes grouped together. 
Immediately behind the head, and articulated 
with it, is the very narrow segment which bears 
ventrally the poison claws. Behind this are 
fifteen similar segments, nine of which are 
larger than the others, and somewhat irregularly 
arranged ; each segment is covered dorsally by 
a squarish tergum ; the difference in size of the 
segments is not apparent on the ventral surface, 
the sterna being all of the same size. The terga 
and sterna are connected laterally by a soft 
flexible skin which bears the stigmata. 
Appendages of Lithobius forficatus. 
1. Antennae. 4. Limb-like appendages. 
2. Mandibles, 5. Poison claws. 
3. Maxillae. 6-20. Fifteen walking-legs. 
The appendages are: (i.) the antennae; (ii.) 
a pair of mandibles with a toothed cutting edge, 
they are jointed, but, like those of Insects, are 
devoid of a palp (Fig. 178); (ai.) a pair of 
maxillae, consisting of a palp and a fused median 
portion; (iv.) a pair of limb-like appendages 
turned forward, with their bases in contact. 
Behind this are (v.) the poison claws, a pair of 
stout large claws which contain in their last 
two joints the poison gland; the duct of this 
opens on the convex side of the apex. In 
Scolopendra a large basilar segment succeeds the 
head; this consists of four embryonic segments 
Fie. 177. — Scolo- 
pendra morsi- 
tans. After 
Buffon. 
a. Cephalic tergite. 
6. Basilar tergite. 
c. First postceph- 
alic appendage 
(=third postoral), 
d. Third postceph- 
alic appendage. 
e. Antenna, 
J. Second — postce- 
phalic appendage 
(=poison claw). 
g. Last pair of ap- 
pendages enlarged 
and turned back- 
wards, 
fused, and bears iv. and v., and sometimes a pair of walking 
legs, but the latter are frequently lost in the adult (Fig. 177). 
They do not occur in Lithobius. 
The remaining fifteen segments bear each a 
pair of seven- 
jointed legs, arising on the lateral margin of the ventral sur- 
