Two of the principal writers on the classification of the Myriapods are Koch and Latzel, both of whom have classified the whole group. I do not wish for a moment to undervalue the many authors who have done excellent work on the classification of different groups and families, but I wish here to give an outline of a classification of the whole class, and I naturally have recourse to the authors who have treated the subject as a whole.
Koch's two works, the System der Myriapoden[[13]] and Die Myriapoden,[[14]] cover the whole range of the class, and his divisions are clearly marked out and are easily understood, but both works are comparatively old. He does not include the Scolopendrellidae or the Pauropidae, which are now included by all naturalists in the Myriapoda. Latzel is a more recent writer, and though his work is entitled The Myriapods of the Austro-Hungarian Empire,[[15]] he gives much information about Myriapods not found in Europe, and his work is fairly entitled to be considered as embracing the whole class. He divides the Myriapods into four Orders, including the Scolopendrellidae and Pauropidae. On the whole, I think it will be better here to take the classification of Koch, and to add to it the two Orders before mentioned, viz. Symphyla containing one family the Scolopendrellidae, and Pauropoda with one family the Pauropidae.
The Orders are as follows:—
Order I. Chilognatha (= Diplopoda)
Antennae 7 joints, three anterior body rings with one pair of legs to each ring. Posterior rings with two pairs of legs to each. Genital organs opening ventrally on the anterior rings of the posterior part of the body, i.e. on one of the anterior of the segments bearing two pairs of legs; usually the 7th.
This Order is divided into eight families:—
Family 1. Polyxenidae.
Ten body rings, not counting the neck-plate. Thirteen pairs of limbs. Eyes hard to find, on the lateral corner of the head (Fig. 18, p. [37]).
Family 2. Glomeridae.
11 body rings. 17 pairs of legs. Eyes arranged in a row curved outwards.