158 CRUSTACEA—EUCARIDA—DECAPODA CHAP. 
had managed to survive where the competition was not so keen. 
The genus Willemoesia is very widely distributed, being dredged 
up from below a thousand fathoms 
in the Indian Ocean, the Mediter- 
ranean, North and South Atlantic, 
and the Pacific oceans. All the 
walking legs are chelate, and the 
animal is quite blind, as are all 
the Eryonidea, the eye-stalks being 
fused with the carapace. 
Only a single family Eryonidae 
is recognised. 
Tribe 3. Peneidea.—tTribe 4. 
Caridea. 
We will now consider the 
Shrimps and Prawns, since in 
them occurs the most complete 
metamorphosis found in the Deca- 
poda. The Peneidea are dis- 
tinguished from the ordinary 
Prawns and Shrimps (Caridea) 
by having the first three instead 
of the first two pereiopods chelate. 
The genus Peneus affords several 
species which are of commercial 
value as objects of food; the 
edible Prawns of the Mediter- 
Fic. 105.—Willemoesia tnornata, x 3. yanean belong to this genus, while 
(From a figure prepared for Pro- . 
fessor Weldon.) in the North Sea two of the 
Caridea, viz. the Shrimp, Crangon 
vulgaris, and the Prawn, Palaemon serratus, are the forms very 
commonly eaten. Both subdivisions are well represented in the 
deep sea fauna from all parts of the world.  Glyphoerangon 
spinulosa (Fig. 110, p. 164) is a deep sea Shrimp with eyes that 
have lost their pigment, and with the body covered with spines, 
while the last abdominal segment is fused with the telson 
to form a sharp bayonet -like process at the hind end of the 
body. Some of the deep-sea Prawns of the Indian Ocean 
