14 HYPERIID. 
We believe that Professor Milne Edwards was the first 
to point out the great difference of form existing between 
the young and the adult in this division of Amphipoda ; 
but Mr. Gosse, in his pleasant “ Naturalist’s Rambles in 
Devonshire,” has figured the young of this species. We 
also have had an opportunity of examining them, a 
drawing from which is given at figure -u * at the head of 
this description. The head of the young animal is 
small, and the eyes, consequently, are not much deve- 
loped. The body is very large, while the tail is narrow 
and straight, and lies compressed beneath the body. Mr. 
Gosse has figured all the legs, but in our specimen two 
pairs appeared to be wanting. This may be accounted 
for by the circumstance that Mr. Gosse’s specimens were 
older than ours, he having procured his as free and inde- 
pendent creatures, whereas ovrs were procured direct 
from the incubatory pouch. In the caudal appendages 
there also appears to be a difference in the degree of 
development as observed by Mr. Gosse and ourselves, 
arising, no doubt, from the above-named cause. 
This species, which must be considered as the type of 
the genus, was first taken by Col. Montagu on the 
southern coast of Devonshire, and it has been sent to us 
from Jersey by Mr. George Parker. Specimens from a 
Rhizostoma at Lamboy in Ireland have been communi- 
cated to us in Mr. W. Thompson’s collection, belonging 
to the Belfast Museum, and a number of specimens stated 
to have been also captured in the stomach of a Medusa, 
and given to us by the late lamented Rev. Professor 
Henslow. Mr. White records it as inhabiting the pouches 
of Rhizostoma Cuviert on the Dublin coast upon the autho- 
rity of Mr. Hyndman. Mr. Edward has sent it to us from 
* This mark is intended to symbolize the young animal. 
