Soiitli African Crustacea. 91 



GEN. SPIRONTOCAEIS, Bate. 



1888. Spirontocaris, Bate, Eep. Yoy. Challenger, vol 24, pp. x, 576, 



595. 



1898. \Yalker, Tr. Liverpool Biol. Soc., vol. 12, p. 276. 



1904. ,, Rathbun, Decap. Crust. NW. Coast N. America, 



pp. 5, 56-107. 

 1906. ,, Norman and Scott, Crustacea of Devon and 



Cornwall, p. 18. 

 1906. Caiman, Ann. Nat. Hist., Ser. 7, vol. 17, 



pp. 31, 32. 



1910. ,, Kemp, Fisheries Ireland, 1908, i., pp. 99, 102. 



1914. ,, Balss, Abhandl. K. Bayer. Ak. Wiss., vol. 10, 



Suppl. 2, p. 42. 



Through the above references there may be traced a large 

 literature relating to this rather perplexing genus. The 

 species now offered as an additional member of its numerous 

 horde does not conform with the original definition, as it is 

 devoid of the two supraorbital teeth therein mentioned, its 

 rostrum is not deep, and the incisor process of the mandible 

 cannot be called rudimentary. One or other or both of the 

 first two deficiencies, however, it shares with several other 

 species, and with regard to the third precise information is in 

 most cases wanting. The mouth-organs are suggestive of 

 agreement with Bate's Hetairus, but if that genus were 

 resumed from the synonymy of Spirontocaris, Bate's state- 

 ment that the third maxillipeds are without an exopod must 

 be noted as erroneous. 



SPIROXTOCARIS PAX, n. sp. 

 Plate LXXXYIII. 



The species to which the present appears to make the nearest 

 approach is Spirontocaris crancliii (Leach), 1817, which in turn 

 closely resembles the rare form from Japan named Hippolyte 

 gracilirostris by Stimpson in 1860, and transferred to Spirontocaris 

 by Balss in 1814. Here the slender rostrum carries dorsally 4 teeth 

 instead of 6 as in Stimpson's species, a smooth space being left 

 anteriorly which his occupies with the 2 foremost teeth ; ventrally 

 there are 2 small teeth just behind the apical point in Balss's figure 

 of the other species. In S. crancliii the 3 or 4 rostral teeth 

 approach the bifid or trifid apex more nearly than here. In all 



