590 GEOLOGICAL SURVEY OF THE TERRITORIES. 
EXPLANATION OF PLATE XXXVIII. 
Lettering. 
a, first pair of antenne. 
a?, second pair of antenne. 
md, mandibles. 
mo, first pair of maxille. 
ma?, second pair of maxille. 
po’, first pair of thoracic feet. 
po”, second pair of thoracic feet. 
th. l, thoracic feet. 
ab. f, abdominal feet. 
e@, esophagus. 
ep, epithelium of stomach. 
p. d, procephalic or antennal lobe. 
st, stomach. 
Fig. 1. Embryo of Nebalia geoffroyi in the Nauplius stage. 
Fig. 2. The same, farther advanced, with the rudiments of the cephalic and first two 
thoracic appendages and the hind gut. 
ric. 3. The same, still more advanced, the biramous thoracic feet developed. 
Fre. 4. Embryo of the same nearly ready to hatch. 
Trg. 5. Embryo at the time of hatching. 
Figs. 1-5 copied from Metschnikoff. 
Fic. 6. Embryo of Schizopod Pseudomma roseum. Copied from Sars. 
