Packard.] 202 [June 16, 
As embryological proofs of our morphological views may be taken the 
admirable researches of Metschnikoff* on the development of Geophilus. 
His Taf. xx, fig. 4, shows plainly the four pairs of mouth-appendages be- 
hind the antenne, the latter developed as in Hexapods from the proce- 
phalic lobes. His fig. 15 shows that the pleurum and tergum of two poste- 
rior (or fourth and fifth) cephalic arthromeres, with their appendages, are 
the primitive scuta of the proto and dentomalar arthromeres which at this 
period have coalesced, and are intimately united with the procephalic lobes. 
His fig. 18 shows that at a later peviod the primitive scuta of the fourth 
cephalic segment has disappeared, or at least is merged into the fifth 
primitive scuta or sub-basilar plate of the adult. An examination of 
Metschnikoff’s paper will prove conclusively that Newport’s views as 
to the sub-segments of the chilopods are not well founded in nature ; and 
that they are merely for the most part simply adult superficial markings. 
The following table will serve to indicate, in a comparative way, the 
number of arthromeres in the head of the three sub-classes of Tracheate 
arthropods, their corresponding appendages, and the more important syn- 
onyms: 
Hexapoda. | Arachnida, Myriopoda. Myriopoda, 
| (Chilopoda ) | (Chilognatha.) 
nt Boma Antennee, Wanting.t Antenne. Antenne, 
reoral) 
2d Arthromere|Mandibula. Chelicerese.t Protomale. Protomale. 
(Postora]) (Mandibles.) (Mandibles Sa-|(Mandibles Sa- 
vigny.) vigny.) 
8d Arthromere|ist Maxille. (Pedipalpi, Deutomale. Deutomale. 
maxillee.)} (1st Maxillee Sa-|(Labium.) 
| | BET tot A 
4th . ../2d Maxillee. Ist pair of bee-|Ist Malipedes, |2d pair of Pedes. 
nopoda. (Ist Auxiliary 
| lip, Savigny.) 
5th. ti aero or vidas -».(2d pair of bee-|2d Malipedes.|2d pair of Pedes. 
| nopoda, (Auxiliary 
lip, Savigny; 
Mandibles.) 
6th bi ..|Ist pair of bee-/8d pair of bee-|Ist pair of Pedes|3d pair of Pedes. 
nopoda. nopoda. 
General Morphology of the Body. The well-known researches of New- 
port on the development of Julus, and the embryological studies of Met- 
schnikoff already referred to, show that the larva of Julus and other diplo- 
pod myriopods is hatched with but three pairs of feet. In Julus terrestris, 
as stated by Newport, the 8d body-segment is apodous; the 1st, 2d and 
4th segments behind the head bearing feet. The number of body-segments 
are at first 9; the new segments appearing six at a time. In Strongy- 
* Embryologisches, tiber Geophilus. Von Elias Metschnikoff. Zeitschrift far 
Wissenschaft. Zodlogie, xxv, p. 818, 1875. 
+ Balfour claims that the Ist pair of cephalic apppendages are wanting; and 
the fact shown by his Fig. 200 C, D, that the stomodseum at first lies between the 
procephalic lobes, and that the latter do not even bear appendages appears to 
prove his statement, 
{On the Organs of Reproduction and the Development of the Myriopoda 
Phil, Trans,, 1841, 
