Contributions to the Crustacean Fauna of South Africa. 419 



5-7 narrower than 4, gradually decreasing in width, 5 shortest dorsally, 

 6 shortest laterally, 7 of equal width throughout, all the segments 

 with transverse ridges marking the anterior and posterior margins, 

 the anterior ones on segments 1-3 very faintly denticulate in two 

 of the specimens ; side-plates distinct on first 4 segments. 



Pleou a little longer than 6th and 7th peraeon segments together, 

 only a little narrower at base than 7th segment, basal margin 

 straight with a transverse ridge, narrowing to a subacute apex, lateral 

 margins straight except for a slight convexity above the insertion of 

 the uropods. 



Antenna 1, 1st joint subtriangular, outer apex subacutely produced, 

 with 2 spines, outer margin with 2 spines near base and 1 in middle, 

 inner margin with 3 spines just before insertion of 2nd joint, 3rd 

 more slender than 2nd and a little longer, flagellum about equal to 

 2nd plus 3rd joints, 6-jointed, 1st joint shortest. 



Only the basal joints of antenna 2 remaining. 



Mouth-parts as figured by Sars for I. longicornis (1897, I.e. pi. 59). 



Peraeopod 1 also as in longicornis. All the other peraeopods lost. 



Operculum in $ ovate-lanceolate, with a strong and sharp median 

 longitudinal keel reaching almost to the subacute apex. 



Uropods lost. 



Length: 5mm.; breadth: l - 75 nun. 



Colour : In spirit pinkish-white. 



Locality: Cape Point N. 89 E., distant 36 miles. 700 fathoms. 

 4 nouovigerous ? ? . s.s. " Pieter Faure." 20/8/03. (S.A.M. No. 

 A4065.) 



Very close to longicornis from the N. Atlantic, but distinguished 

 by having the outer angle of the 1st joint of 1st antenna produced 

 instead of the inner, and by the 5th peraeon segment being very 

 distinctly narrower than 4th (thereby distinguished also from plunketti 

 Tattersall, I.e. p. 28, pi. 7 *), with straight or very slightly emarginate, 

 instead of convex, sides. The denticulation on the anterior margins 

 of the first 3 segments is a variable feature (cf. Ohliu's remarks on 

 hirticeps and denticulata in I.e. supra, p. 36). 



ILYAKACHNA CRASSICEPS u. sp. 



Body smooth, glabrous. Head broader than long, the lateral 

 portions not very pendulous, no transverse ridges on anterior or 

 posterior margins. Peraeou segment 1 narrower than head, very 

 short ; segment 2 longer and wider, both 1 and 2 laterally obtuse ; 

 segment 3 with acute autero-lateral angles ; segment 4 longer than 3, 

 * But see Haiiseu, I.e. 1916, p. 122. 



