BRITISH STALK-EYED CRUSTACEA. 469 
whereas those from a muddy estuarine locality are dark and 
dirty-looking: in fact, so completely does Crangon vulgaris 
resemble in tint the bottom on which it lives, that it is abso- 
lutely impossible to detect it when motionless. I have frequently 
observed this in shallow clear water where Shrimps almost 
covered the sand; and yet, when not actually moving, not an 
outline could be traced or a single living thing seen, but on 
alarm hundreds of little flashes showed where these thoroughly 
invisible little things really were. I have, when collecting, 
touched them with my hand, and caught a momentary glimpse 
of them when something, such as a white shell or pebble, served 
as a background to show them up. 
The Shrimp is an exceedingly common coast crustacean, and 
is much fished for, being such a generally recognised article of 
food. Who has not heard of the celebrated Shrimps of Pegwell 
Bay? I fancy from what I have seen of its distribution that it 
prefers the sandy stretches on the shores of cretaceous rocks to 
others, for in some localities it is by no means common, ani 
these are spots of a different geological character. It has been 
recorded specially from Shetland, Dublin, Galway, Belfast, 
Berwick, the Hebrides, and from the Adriatic Sea; perhaps 
nowhere is it finer than from the estuaries of the Thames and 
the Stour. Its crustacean characteristic of having its spines, 
&c., pointing forwards is not always so conducive to its welfare 
as might be supposed. I once found a Shrimp in a tube of an 
Annelid, Pectinaria belgica ; this tube is conical and composed of 
grains of sand cemented together. The Shrimp had backed into 
this empty tube tail first, expecting probably to get right through, 
but this of course was impossible, and so was it for him to get 
out again the way he had got in, for his spines prevented this 
most completely. How many crustaceans may destroy them- 
selves in this way ? 
I may mention that the best way to tell the true Shrimp 
from other inferior crustaceans that are sometimes sold as 
Shrimps (I mean before they are boiled), is that the true Shrimp 
is flat on the head-part; and other sorts likely to be offered as 
Shrimps have a rostrum or sort of comb on the back of the 
head and projecting between the eyes. 
(To be continued.) 
