338 Dr, A. 8. Packard, Jun., on the 
characters ; it is emarginate on the sides, with a deep median 
notch containing three acute teeth. The labrum may on the 
whole be regarded as homologous with that of the Hexapoda, 
but is very broad and is immovable. Very different is the 
so-called labrum of the Chilognaths, which consists of two 
parts, a central portion, which may be homologized with 
the labrum of the Chilognaths, but is narrower, with a deep 
broad median notch, at the bottom of which is a central stout 
tooth. 
In Orya barbarica, Gerv., according to Meinert, the labrum 
has a median suture, dividing it into two pieces, each with 
numerous fine teeth on the outer edge. 
In Dignathon microcephalum, Lucas (Meinert, tab.ii. fig. 15), 
and in Geophilus sodalis, Kgs. and Mein., Meinert figures and 
describes the labrum as consisting of a pars media and two 
partes laterales, distinctly separated by suture ; no such diffe- 
rentiation as this is known to us as occurring in the labrum 
of Hexapods. 
This labrum is flanked on each side by a transverse sclerite, 
much broader than long; these pieces may be called the epa- 
labra; to the outer edge of each is attached the cardo of the 
so-called mandible ( protomala}. What we have for brevity 
called the epdlabra (fig. 1) are the “ laminze fulcientes labri ” 
of Meinert *. 
The so-called mandibles of the Myriopods are the morpho- 
logical equivalents of those of insects, but structurally the 
are not homologous with them, but rather resemble the lacinia 
of the hexapodous maxilla. For this reason we propose the 
term protomala (mala, mandible) for the mandible of a Myrio- 
pod; mala would be preferable, but this has already been 
applied by Schiédte to the inner lobes of the maxilla of certain 
Coleopterous larve. 
The protomala consists of two portions, the cardo and stipes, 
while the hexapodous mandible is invariably composed of but 
one piece, to which the muscles are directly attached, and 
which corresponds to the stipes of the Myriopodous protomala. 
The stipes, instead of being simply toothed or with a plain 
cutting edge, as in Hexapoda, has, in the Chilognaths, two 
outer unequal long teeth, and within a series of singular pro- 
cesses like stout setee, edged with dense spines on the inner 
side. ‘This double apparatus of teeth and spiose processes, 
* “ Myriapoda Museei Havyniensis. Bidrag til Myriapodernes Mor- 
phologi og Systematik,” ved Fr. Meinert; ‘ Naturhistorisk Tidsskvift, 
3 R. 7 B. (Kjobenhavn, 1871), p. 105 (see tab. i. fig. 4). Meinert states 
that the lamune fulcientes do not belong to the labrum itself, and that the 
form of these pieces varies greatly according to the species. 
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