268 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 nagella of the antennae, since in the young of 

 E. cuspidatus each articulus is longer than those in the 

 adult. 



