or P. simplex (Bate) ? 157 



after several years in spirit as when freshly caught, while in 

 Bate's species they were (like P. HolhoUi) " not appreciable." 

 The relative proportions of the flagellum and secondary ap- 

 pendage in the upper and the general character of the lower 

 antenna are totally different. I agree with Mr. Caiman that 

 Bate's specimen was an immature male ; but he has tlien to 

 account for the fact that while it measured^ inch, or about 

 4 millim., in length, an adult male of P. pectinatus is only 

 3 millim. long, a difference which is more than confirmed by 

 comparison with the type specimen at the British Museum. 

 Unfortunately this specimen is in such bad condition that a 

 detailed examination is impossible without dissection. 



Phoxus simplex, Bate (Cat. of Am- Phoxoccphalus pecttnaUts, Walker, 

 phipodous Crustacea, 1862). female. 



Generic Character. 



Eyes not appreciable. Eyes in both sexes large and 



dark, retaining their colour in spirit 

 for years. 



Specific Characters. 



Superior antennae having the Superior antennae having the ex- 

 extremity of the Jlagelhcm not reach- tremity of the peduncle reaching to 

 j«5/ beyond the anterior margin of the anterior margin of the cephalon; 

 the cephalon ; the flagellum short, flagellum /oM/--joiuted ; secondary 

 iAree-jointed; secondary appendage appendage much shorter than the 

 longer than the primary, four- primary, four-jointed, 

 jointed*. 



Inferior antennae as long again as Inferior antennaj half as long 



the superior ; the joints of the pe- aya«t as the superior ; the peduncle 



duncle scarcely distinguishable from quite distinct from the flagellum. 

 those of the flagellum. 



Length of immature male 4 mm. Length of adult male 3 mm. 



Alfred 0. Walker. 



Nant y Glyn, Colwyn Bay, 

 July 1, 1896. 



• In the Brit. Sess.-eyed Crust, the secondary appendage is said to be 

 three-jointed, while the " primary " (flagellum) is four-jointed, the former 

 being " nearly as important " as the latter. The figure, however, shows 

 the secondary appendage much shorter ; but as in his earlier description 

 Bate seems to have mistaken the appendage for the flagellum, the descrip- 

 tion is probably more accurate than the figure. 



