38 Annals of the South African Museum 



AMPHIPODA. 



TRIBE GAMMARIDEA. 

 FAMILY LYSIANASSIDAE. 



GEN. ICHNOPUS, A. Costa. 



For these systematic divisions I may refer to Das Tierreich, 

 Lieferuug 21, pp. 1, 5, 6, 52, published in 1906. Here, however, I 

 must add hearty thanks to my friend A. 0. Walker, Esq., F.L.S., 

 who has sorted into their genera a mass of South African Amphi- 

 poda, a tedious and time-absorbing task, even when lightened in his 

 case by extensive knowledge of the subject and long-continued interest 

 in it. Ichnopus serricrus, Walker, was added to the genus in 1909. 



ICHNOPUS MACROBETOMMA, n. sp. 

 Plate XCVlA. 



This species is at once remarkable for the large dark eyes, with 

 innumerable little components, occupying almost the whole surface 

 of the head, at the top of which they are contiguous, while in lateral 

 view the front outline of each eye suggests a capital B, to which 

 formation the specific name refers. There are many points of agree- 

 ment with I. spinicornis and I. taurus, the approximation being the 

 closer to the latter species, the palp of the first maxillae having the 

 peculiar widening of its distal joint just below the spine margin, as 

 shown in Heller's figure, and the finger of the first gnathopod being 

 of the structure which he shows, except that here there are ten spines 

 on its widened base. 



The first antennae have a secondary flagellum of ten joints, the 

 first of them considerably the longest. The mandibles are similar to 

 those which Delia Valle figures for I. taurus, differing from those 

 figured by Sars for I. spinicornis, though the palps agree. In our 

 specimen between the cutting edge and molar there is a spine row 

 of very short spines, perhaps worn down by use ; on the upper edge 

 of the retro verted molar there are prominent teeth, none visible on 

 the lower edge, the reverse of this appearing in Delia Valle's figure. 

 Of the inner plate of the first maxillae I cannot speak, as it was 

 unfortunately broken. Heller's figure of it for I. taurus does not 

 agree with Delia Valle's. 



In the first and second peraeopods the fourth a,nd sixth joints are 

 longer than the fifth, this and the fourth being fringed with setae on 



