344 Dr. A. 8. Packard, Jun., on the 
way the number of arthromeres in the head of the three sub- 
classes of ‘T'racheate Arthropods, their corresponding appen- 
dages, and the more important synonyms :— 
lst Arthromere 
(Preoral). 
2nd Arthromere 
(Postoral). 
ord Arthromere 
Hexapoda. 
Antenne. 
Mandibula. 
Ist Mavxille. 
2nd Maxille. 
eeeseene 
Ayachnida. 
Wanting *. 
Chelicere f. 
(Mandibles.) 
(Pedipalpi, max- 
illee.) 
Ist pair of baeno- 
poda, 
| 2nd pair of beeno- 
poda. 
Myriopoda 
(Chilopoda). 
Antenne. 
Protomalze. 
(Mandibles, Sa- 
vigny.) 
Deutomale. (Ist 
Maxille, Sa- 
vigny.) 
Ist Malipedes. 
(1st Auxiliary lip, 
Savigny.) 
2nd = Malipedes. 
(Auxiliary lp, 
| 
| 
: 
eee 
Antennee. | 
! 
| 
Myriopoda 
(Chilognatha), 
Protomale. 
(Mandibles, § 
vigny.) 
Deutomale. 
| 
(Labium.) | 
2nd pair of Pede| 
| 
2nd pair of Pede 
Savigny ; Man- 
dibles. ) 
Ist pair of beeno-) 3rd pair of beno-| 1st pair of Pedes. | 3rd pair of Pede| 
poda. 
poda. 
General Morphology of the Body.—The well-known re- 
searches of Newport on the development of J/u/us, and the 
embryological studies of Metschnikoff already referred to, show 
that the larva of Julus and other diplopod Myriopods is 
hatched with but three pairs of feet. In Julus terrestris, as 
stated by Newport, the third body-segment is apodous, the 
first, second, and fourth segments behind the head bearing 
feet. [he body-segments are at first nine in number, the 
new segments appearing six at a time. In Strongylosoma, 
according to Metschnikoff, the larva has eight segments be- 
hind the head, the second segment footless ; in Polydesmus 
there are but seven body-segments, the second apparently 
being apodous, though it is difficult to determine with certainty 
from the drawing which of the first three segments is apodous. 
In two embryos of Julus multistriatus, Walsh ?, kindly 
communicated to us by Prof. Riley, and which he assures us 
* Balfour claims that the first pair of cephalic appendages are wanting ; 
and the fact shown by his fig. 200, C, D, that the stomodzeum 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. 
