PROCEEDINGS OF SCIENTIFIC SOCIETIES. 501 
latter part of embryonic life. Unlike the Crustacea generally the prim- 
itive band is confined to a minute area, and rests on top of the yolk, 
as in the spiders and scorpions, and certain Crus- Fig. 101. 
tacea, i. e., Eriphia spinifrons, Astacus oyee 
Palæmon adspersus, and Crangon maculosus, in 
which oe is 
Fig. 99. 
: t : Larva of Trinucleus orna- 
plius skin about tus, natural size, and en- 
; larged. 
embryonic life. Fig. 102. 
This Nauplius m 
skin corres- 
nds in some 
" 
e 
un 
"3 
oO 
i) 
e 
n 
ct 
o 
e 
o 
c 
D 
Larva of Limulus, natural size, nå  . of eee em- 
enlarged. 
ryol 
The recently hatched young of pet ae wes lm rira, "esf 
H4 
can scarcely be con nsidered a Nauplius, like t 
Fig. 103. Fig. 104. 
Larva of Agnostus nudus, Adult Agnostus nudus, 
nat. size, and enlarged. nat. size, and enlarged. a Laces ot Apst. 
b Larva of Branchipus. 
figured by Barrande qne. 101, larva of Trinucleus ornatis ; Fig. 102, larva 
of Sao hirsuta; Fig. 103, larva of Agnostus nudus) which are in Trinu- 
cleus and Agnostus born wits only the cephalothorax and pygidium, the 
