198 Annals of the South African Museum. 



GEN. TANAIS, Audouin and M. Edwards. 



1828. Tanais, Audouin and M. Edwards, Precis d'Entomologie, vol. 1, 



p. 46, pi. 29, fig. 1. 



1832. Anisocheirus, Westwood, Ann. Sci. Nat. vol. 27. 

 1836. Zeitxo, Ternpleton, Tr. Entom. Soc. vol. 2, p. 201. 

 1843. Crossurus, Eathke, Fauna Norwegens, p. 35. 

 1886. Tanais, Beddard, Challenger Eep. vol. 17, pt. 48, p. 119. 

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



Eep. 23, p. 2. 

 1905. ,, Eichardson, Bull. U.S. Nat. Mus. No. 54, p. 7. 



TANAIS SPONGICOLA, n. sp. 

 (Plate XVII. A.) 



Body evenly cylindrical, smooth with the exception of a few hairs 

 along the anterior margins of the peraeon segments. 



Head longer than its greatest width, eyes small but distinct, 

 situated on and forming the antero-lateral angles, front margin 

 between them flatly angular. 



First segment of peraeon visible only at sides, second (first free) 

 segment narrow, the following ones gradually increasing in length, 

 but in none of them does the length equal the breadth, none of the 

 side-plates except the first as long as their respective segments, the 

 first acutely produced anteriorly. 



Pleon composed of 6 distinct segments, lateral margins rather 

 densely setose, 4th and 5th segments not markedly narrower than 

 lst-3rd, 6th segment broader than long, apex rounded, with 3-4 setae, 

 a median groove on postero-inferior face. 



First antenna, 1st joint 5 times as long as broad, 2nd joint a little 

 more than one-fourth length of 1st, 3rd joint one-third length of 2nd, 

 4th joint (= flagellum) minute, with strong brush of setae. 



Second antenna about as long as first antenna, 1st joint a little 

 longer than 3rd, its margins minutely serrulate, 2nd joint a little 

 shorter than 4th, which is half the length of 3rd, 5th joint minute, 

 with strong brush of setae. 



Upper lip bluntly rounded, with thick fringe of setae, epistome 

 narrow, strongly calcified. 



Lower lip, outer lobes indented on exterior margin, lower portion 

 spinulose on margin, apex with a minute setulose "palp," inner 

 lobes as long as but not as broad as outer, evenly rounded, apices 

 setulose. 



