THE GENERAL SUBJECT. 
Myr . 3 
figured as a larval form of an Isopod Crustacean by the late David Pago 
in liis “Advanced Text-book,” 1st edn., p. 135, fig. 4) and Archidesmus 
macnicolli (g. & sp. nn.) ; they are the oldest animals as yet described? 
and of simpler construction than any other known Chilognatha. The 
body segments are all free, and each bears but one pair of legs. 
20. Ryder, J. A. Genera of the Scolopendrellidce. P. U. S. Nat. Mus. 
v. p. 234. 
There are two forms of this group : — 1. Scolopendrella , Gervais, slender, 
tapering anteriorly, stomata on upper surface of elongated head ; S. 
notaccintha, Gervais, and S. microcolpa, Muhr. 2. Scutigerella , g. n., 
broader, of nearly uniform width, stomata lateral, head nearly circular, 
appendages of legs more developed ; S. immaculata , Newp., and S. gratice, 
Ryder. 
21. Scudder, S. H. Archipolypoda, a subordinal type of spined Myrio- 
pods from the Carboniferous formation. Mem. Bost. Soc. iii. 
pp. 143-182, 4 pis. 
Describes known Archipolypoda which are comprised in four genera : — 
1. Acantherpestes, Meek & Worthen, with three rows of spines on each 
side. 2. Euphoberia, Meek & Worthen, with two rows of spines on each 
side. 3. Amynilyspes, g. n., with one row of spines on each side. 4. 
Eileticus , g. n., with tubercles merely, not spines. 7 new species are 
described. 
22. . The affinities of Palccocampa , Meek & Worthen, as evidences 
of the wide diversity of type in the earliest known Myriopods. Am. 
J. Sci. (3) xxiv. pp. 1G1-170 ; Ann. N. H. (5)x. pp.28G-295. Abstract 
in J. R. Micr. See. (2) ii. pp. 773 & 774. 
Palccocampa is neither a worm nor the larval form of a Lepidopterous 
insect, but a Myriopod. The examination of it brings out two remark- 
able facts : first, the extraordinarily high organization of the dermal 
appendages in these ancient Myriopods ; and, secondly, that at a very 
early period there was almost as great a divergency in the structure of 
Myriopods as there is at the present time. It is probable that Myriopoda 
appeared before Insects, and that the earlier types were aquatic. Scudder 
wonders that Myriopoda should not have been found in strata older than 
the carboniferous. [Cf. Peach, supra .] 
23. Sograff, N. Zur Embryologie der Chilopoden. Zool. Anz. v. 
pp. 582-595. 
Describes the earlier stages of development in the egg of GeopJiilus 
ferrugineus and G. proximus. The egg while in the oviduct is enveloped 
in a transparent coat formed of the united chorion and yelk-membrane ; 
it is fillod with yelk which conceals the germinal vescicle and yelk 
nucleus. On one occasion a nucleated mass of protoplasm was observed 
in the centre. The nucleus and protoplasm divide into a number of 
cleavage masses, stellate at the periphery, round or polygonal at the 
centre. Yelk-cleavage then follows, the yelk breaking into pyramidal 
masses bearing portions of protoplasm at their apices. This cleavage is 
not dichotomous. In all cases < bserved the number of these pyramids 
1882. [vol. xix.] c 13 
