Mr. J. Wood-Mason on Scolopendrella. 55 
group*, describing a new species, and giving a useful sum- 
mary of Menge’s important paper. 
In 1881 } there appeared a paper by Dr. Jos. Muhr which 
is said to contain a valuable description of the mouth-parts of a 
new species closely allied to S. notacantha, but which I have 
not yet seen. 
Finally, in the present year Dr. 8. H. Scudder, of Cam- 
bridge, Mass., U. 8S. A., described a new species under the 
name of S. latipes. 
I have arrived at the conclusion that Scolopendrella is a 
Myriopod which, while resembling the Chilopoda in the form 
of the body, is more nearly related to the Chilognatha; but 
whether it should be classed as a suborder of the latter or in 
an order by itself we shall be better able to say when we 
shall have learnt more about its anatomy and development than 
we at present know. And I regard it as the descendant of 
a group of Myriopods from which the Campodee, Thysanura, 
and Collembola may have sprung, looking upon the three 
latter groups as the living representatives of the extinct stock 
or stocks from which the various orders of insects have origi- 
dnate,—the jointed (Myriopodous) mandibles and the presence 
of two pairs of appendages (the one a pair of walking-legs and 
the other a pair of styliform rudiments) on each of the two 
hinder thoracic somites, and of two pairs of rudimentary feet 
on each of two of the abdominal somites, in Machilis seeming 
to me explicable only on the hypothesis that this form is de- 
scended from an animal allied to the Chilognatha, and the 
somites of whose body were provided with two sterna, each 
furnished with a pair of appendages of the value of legs; and 
the resemblances of the true insects through Blatta to the 
Entomopsida (Campodez, Thysanura, and Collembola), on the 
hypothesis that the two have a common ancestry. 
Seeing that there occur in combination in Scolopendrella 
two of the most remarkable features of Peripatus, namely two- 
clawed feet and segmental openings, its ancestry may be in- 
ferred to have lived and flourished before the present types 
of Myriopoda were evolved ; and it may therefore throw much 
light on the origin of Myriopods also: it may, for example, 
atford an explanation of both the modes of addition of fresh 
segments—that which “ takes place by the way of intercala- 
tion at each moult in the intervals between each pair of older 
segments,’ and that by their interposition between the penul- 
* Proc. Acad. Nat. Sci, Phil. 1881, pp. 79-86. 
T Zool. Anz, iv. 1881, pp. 59-61, figs. 1, 2, and 4. 
