388 



AMPHIPODA. 



NATATOR1A . 



OAMMARnXE. 



GAMMARJDES. 



GAMMARUS PULEX. 



Specific character. Very much like G. locusta. A few slender cilia mixed 

 with the spines on the dorsal surface of the fourth and fifth segments of the 

 pleon. Eyes reniform, formed of minute black dots. Secondary appendage 

 of the superior antennas slender, rather short, 3-4 jointed. Posterior pair 

 of pleopoda much longer than the preceding pair ; having the rami subequal, 

 subfoliaceous, and with the margin ciliated. Upper antennae rather longer than 

 the inferior ; peduncle of the inferior much longer than that of the superior. 



Length of male ^ inch. 



Cancer pukx. LINNAEUS, Syst. Nat. 1055 ? Krebsformiger W; 



wurm, FRISCH, Ins. vii. p. 26, fig. 18. 



Squilla pulex. DE GEEK, Memoires, vii. p. 525, t. 33 (certe). 



Astacus pulex. PENNANT, Brit. Zool. iv. 21. 



