768 ZOOLOGY. 
now refer to the larvee of Pycnogonum and Achelia described by 
Dohrn, and especially to the presence of the yolk within the 
maxillæ of the larva of Chelifer, which circumstance connects it 
with the embryology of Phoxichilidium. 
“It is remarkable that the larva* of Chelifer stands still lower 
in its grade of development than the nauplius larve of Crustacea 
and the larvz of the above mentioned Pycnogonids. It indeed 
presents a nauplius form with only two pairs of extremities, but 
in all cases the second pair is completely developed (in the form 
of forked swimming feet) while the same only appears in the 
youngest larva of Chelifer as a stump-like form. 
‘In closing I will remark that in its developmental relations 
` Chelifer differs much more from the Araneina (spiders) and scor- 
pions than Phalangium, the Phrynida, and even the Acarina. 
‘ The writings of Gerstaecker, Claparède and Zalensky, on the 
two last mentioned groups, show us that their embryology agrees 
in many points with that of the Araneina, I can say the same 
from the development of Phalangium opilio observed by me. The 
embryo of this animal resembles in its general features the well 
known embryos of spiders, and differs especially through the want 
of a (provisional) postábdomen, and the relatively less develop- 
ment of the abdomen.” 
The last number of the “ Annales des Sciences” has just come 
to hand containing Balbiani’s memoir “sur la developpement des 
Phalangides.” The eggs and embryo just before hatching were 
so much like those of spiders, that he mistook them for such. 
The earlier stages such as Metschnikoff alludes to he does not 
seem to have noticed. . 
EMBRYOLOGY OF tHE Myriopops.— The only studies on this 
subject of any special value, previous to the researches of Metsch- 
nikoff, are those of Newport on the development of Julus; but 
these do not relate to the earliest changes in the egg. 
In a note to the paper noticed above, Metschnikoff states that 
he has observed a new instance of the total segmentation of the 
yolk in the egg of Polyxenus lagurus and he believes that this 
phenomenon is more widely distributed in the insects and crus- 
tacea than we suppose. “ After the total segmentation of the 
*The embryo is here ref q y asthe term 1 should be restricted to the animal 
after leaving the egg.—Eps. 
