HISTORY OF BRITISH CRUSTACEA. 



pair to each segment of the thorax, and three pairs to the 

 abdomen ; while the jointed tail is armed beneath, and at 

 its end, with foliaceous appendages, that appear to be both 

 motive and respiratory organs."* The head is small and 

 rounded, and the mandibles are concealed. 



Peaniza CiERULEATA, Montagu, sp. Bluish Praniza. 

 (Plate XIII. fig. 4.) — Abdominal segments blue; last seg- 

 ment of abdomen bifurcate at the top ; a line and a half in 

 length. 



Hab. Shores of Devon (Montagu, Linn. Trans, xi. 15, 

 t. 4, fig. 2) ; the male is found usually on rocks, while the 

 female seems to be generally fixed to the branchiae of dif- 

 ferent fishes. 



Montagu, Otto, and Westwood, from finding the Praniza 

 amongst parasitic Crustacea, etc., conclude that like the 

 Caligi they are found on fish. M. Audouint mentions that 

 he and Edwards met with them amongst small Crustacea on 

 the shore of the English Channel, at low water. They were 

 free, and walked about among the seaweeds with their legs. 

 They employ their abdominal appendages in swimming, 

 and have the pieces of their mouths constantly in a state 



* Johnston, Mag. Nat. Hist. v. 521. 



f Note to "Westwood's paper, Ann. Sc. Nat. xxvii. p. 327. 



