amphithoE littorjna. 
423 
brown, and are nearly of the same length, and are not 
quite half the length of the animal;* the inferior have 
the joints of the peduncle armed with strong hairs. The 
first two pairs of legs are subequal, but the second is 
rather the larger. There is a deep semilunar fissure 
between the wrist and the hand and between the wrist 
and the preceding joint, which does not occur in A. rubri- 
cata. The first pair have the hand gradually tapering 
to the extremity; the palm is straight and occupies 
nearly the whole length of the inferior margin. The 
second pair have the hand continuous with the wrist, and 
formed much like that of the first pair ; the palm is long 
and not clearly defined ;f the finger is nearly as long 
as the inferior margin, and has the inner margin smooth. 
The first two pairs of walking legs are short and robust. 
The three posterior gradually increase in length and 
have the inner margins of the hands furnished with a 
longitudinal row of short stout spines. The posterior pair 
of caudal appendages do not reach beyond the preceding 
pair, and have the inner ramus foliaceous and the outer 
styliform, and furnished with two short, hook-like spines. 
The central tail-plate is obtusely triangular. The colour 
of the animal is olive-green, covered all over, especially 
on the sides, with minute black spots — changing when 
dead to a sand colour — and marked on the back with 
numerous impressed punctures. 
This species is generally found amongst the weed close 
in shore, associated with Gammarus locusta . It may 
readily be detected by its size : like ft a Triton amongst 
* Dr. Johnston describes the upper antennae in his G. punctatus as nearly 
as long as the body. 
f Dr. Johnston describes the hands of the second pair as having an obsolete 
tooth. . 
