26 8 
GAMMARIDiE. 
inferior angle of the wrists of the former when compared 
with the latter. But we think that it is not improbable 
that E . Helvetia may be only the young of E. cuspidatus, 
from the fact that in the young animals of E. cuspidatus , 
figured by Mr. Spence Bate in the British Museum Cata- 
logue, the inferior process of the wrists is represented 
by rudimentary lobes only ; these, as they grow in size, 
would probably represent every degree of extension 
between the two extremes. On the other hand the chief 
circumstance that induces us to consider this as a mature 
animal, distinct as a species from E. cuspidatus , is the 
form of the flagella of the antennae, since in the young of 
E. cuspidatus each articulus is longer than those in the 
adult. 
