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.- 

 Caridea. 



-Tribe 4. 



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- 

 FIG. 105. Tnv/,',,,,, ( */ inornate, x >. rane an belong to this genus, while 



(From a figure prepared lor Pro- . 



fessor Weiaon. ) 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. Glypliocrangon 

 spimdosa (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 



