Additional Notes on South African Phyllopoda, 13 



Description. 



The chief dimensions of the specimen are as follows: — 

 Total length from the frontal margin to the end of the last 



caudal segment 26 mm. 



Median length of carapace 11 — 



Greatest width of same 10 — 



Length of exposed part of body , 15 — 



Length of caudal part. 7 — 



Length of caudal filaments 14 — 



The general form of the body in this species also (see 

 fig. 9) is very slender, with the exposed part of consider- 

 able length in proportion to the carapace; and it is very 

 probable that the male Avill prove to be still more slender. 

 Although so far the present species agrees with the preceding 

 one, the females of the two species (comp. fig. 9 with fig. 1) 

 in reality exhibit a rather different appearance. This is 

 chiefly due to the very conspicuous difference in the shape 

 of the carapace. In the present species it is considerably 

 more vaulted and less expanded behind, exhibiting, when 

 seen dorsally, a rather regular oval form, with the greatest 

 width scarcely attaining the median length, and the side- 

 contours but very slightly arcuate. The frontal margin is 

 broadly rounded, and the terminal lobes of the carapace 

 appear broader than in A. namaquensis and less closely 

 appressed to the body. The posterior sinus is rather wide 

 and evenly rounded at the bottom, with the marginal denticles 

 distinct, though rather small. The dorsal keel is well marked 

 throughout its whole length, and the cervical sulcus with 

 its median protuberance likewise very distinct; but there 

 is scarcely any trace of the sabre-like lateral eminences, so 

 conspicuous in the preceding species, and the shell-glands 



