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margin, subapproximated, three times as long as the frontal segment ; 
joints obconic, rather elongated, slightly hairy ; basilar segment qua- 
drate, very short, and much narrower than the frontal, almost atro- 
phied on the dorsal surface ; /abium and inferior surface of the basilar 
segment very large, quadrate, extending backwards beneath the sub- 
basilar segment, with its anterior margin slightly excavated ; mandi- 
bles enlarged, straightened, and projecting, but curved and pointed 
at their apex, with the internal margin acute and denticulated, and 
the basilar joint encroaching on the dorsal surface of the basilar 
segment. Sub-basilar segment large, transverse, with the anterior 
margin straight, and the posterior and angles rounded. Body gra- 
dually tapering ; legs from forty-five to seventy pairs; posterior pair 
styliform. 
Species 1. Mecistocephalus ferrugineus, Koch. 
2. Mecistocephalus mavillaris, Gervais. 
3. Mecistocephalus punctifrons, Newport. 
Frontal segment and mandibles deeply punctured, with the basilar 
segment and labium dark chestnut ; body testaceous, mandibles each 
with two large acute teeth ; legs forty-nine pairs. 
Length two inches three-tenths. India; — Elliot, Esq. 
In the collection at the British Museum. ; 
Frontal segment polished, with small scattered punctures; man- 
dibles very strong, polished, and deeply punctured on the superior 
surface, with the internal margin acute, with two large sharp teeth; 
labium flattened, polished, with a longitudinal depression, and a few 
minute, scattered punctures ; body gradually tapering, but broad and 
strong anteriorly ; legs forty-nine pairs, broad, strong. 
“J am uncertain whether this specimen had arrived at its full 
growth, the number of legs being less than in the other species. It 
may nevertheless have acquired its proper number since the species 
described by M. Gervais has but forty-six pairs, and I have ascertained 
most satisfactorily that the whole of the Chilopoda acquire very nearly 
their full complement of legs before they have attained to one half o 
their adult size.” 
4. Mecistocephalus Guildingii, Newport. 
Frontal segment polished, with a few scattered punctures; sides 
and posterior angles rounded, ferruginous ; mandibles quadridentated ; 
basilar segment and labium polished, ferruginous, with a broad, lon- 
gitudinal sulcus and deep punctures on the latter; body yellowish, 
testaceous ; legs forty-nine pairs. Length one inch and a half. 
Island of St. Vincent. Rev. Lansdowne Guilding. 
In the cabinet of the Rev. F. W. Hope. 
There are five specimens of this species, varying considerably in 
size, but agreeing most accurately in the number of their legs. 
5. Mecistocephalus punctilabium, Newport. 
Head, mandibles, labium and sub-basilar segment ferruginous ; 
mandibles tridentated ; body brownish-green, with the two posterior 
segments antenne and legs ochraceous. Frontal segment and la- 
bium flattened, the latter deeply, and thickly punctured. Legs sixty- 
one pairs. 
