Contributions to the Crustacean Fauna of South Africa. 201 



GEN. GNATHIA, Leach. 



1814. Gnathia, Leach, Edinb. Encycl. vol. 7, p. 402. 



1855. Anceus, Hesse, Comptes rendus, Novernbre 26. 



1858. ,, id. Ann. Sci. Nat. ser. 4, vol. 9, p. 93. 



1863. ,, id. Mem. Savants etrangers, vol. 18, pp. 262, 268. 



1874. Ancaeus, id. Ann. Sci. Nat. ser. 5, vol. 19, Art. 8, p. 8. 



1885. Anceus, Haswell, Proc. Linn. Soc. N.S.W. vol. 9, pt. 4, 



p. 1005. 



1886. Beddard, I.e. p. 135. 



1900. Gnathia, Stebbing, in Willey's Zool. Ees. pt. 5, p. 625 (with 



synonymy). 



1902. ,, Hodgson, Nat. Hist, of the " Southern Cross," p. 241. 

 1905. ,, Stebbing, in Herdman's Ceylon Pearl Fish. Suppl. 

 Kep. 23, p. 8. 



GNATHIA AFRICANA, n. sp. 

 (Plate XVII. B.) 



Head broader than long, with 2 diverging ridges running from the 

 middle of posterior margin to the antero-lateral angles, having above 

 the eyes one prominent tooth and some minor crenulations ; in 

 front of these ridges the head is concave, anterior margin slightly 

 convex and divided apically into 2 bifid lobes with a tuft of setae 

 at their base. 



Peraeon, second segment not quite equalling the greatest breadth 

 of head, laterally quadrate (viewed dorsally), third segment laterally 

 rounded, posterior margin excavate, fourth segment separated from 

 third by a marked constriction, divided dorsally into two halves by 

 a longitudinal depression, fifth segment undivided, sixth segment 

 nearly three times as long as any of the other segments, narrow 

 at base and widening distally, deeply concave between the rounded 

 postero-lateral angles, seventh segment inconspicuous. 



Pleon almost equalling peraeon in length, telsonic segment as 

 broad as long, apex pointed, with 2 setae. 



Larva of the usual form, the fourth and sixth peraeon segments 

 indicated dorsally and laterally on the enlarged portion by stronger 

 and more deeply coloured cuticle, fifth segment only indicated at 

 the sides. 



First antenna $ , 1st joint longer than 2nd, 3rd joint longer than 

 1st, flagellum with 1st joint very short, 2nd joint longest, last three 

 small, inconspicuous, with sensory filaments. 



