South African Crustacea. 3 



GEN. MAMAIA, Stebbing. 



1905. Mamaia, Stebbing, S.A. Crust., pt. 3, p. 23, and Proc. Biol. 

 Soc. Washington, vol. xviii., p. 157. 



Under tbe above references the reasons for discarding the long- 

 accepted generic name Maia and accepting the new form Mamaia 

 are discussed at length. Under the old name an excellent definition 

 of the genus is supplied by Alcock, Journ. Asiat. Soc. Bengal, 

 vol. Ixiv., pt. 2, pp. 237, 238, 1895, and Deep-sea Brachyura of the 

 Investigator, p. 55, 1899. 



MAMAIA QUEKETTI, n. sp. 

 Plate XXVII. 



This species appears to make a near approach to the rare form 

 named Maja (Maja) spinigera by de Haan (Crust. Japon., decas 

 quarta, p. 93, 1839 ; pi. 24, fig. 4, Pisa (Paramaya) spinigera, 1837 ; 

 and M. (Maja) spinig., Errata, p. 244, 1849). It differs in that the 

 frontal spines are more divergent, and instead of one-fourth the 

 length of the rest of the carapace only between a fifth and a sixth 

 of that length. The lateral spines are also less than a fourth of the 

 length named. In the middle line of the carapace there is a longi- 

 tudinal series of conspicuous spines, three before the middle and 

 three behind it, with a little transverse pair between the last two, 

 whereas in de Haan's species there are in this series only two spines 

 instead of five behind the middle. Moreover, in the present species 

 at the middle there is a stout bifid spine, with apices placed trans- 

 versely, of which there is no hint in de Haan's figure or description. 

 The transverse pair of spines on the posterior margin of the cara- 

 pace are here smaller and wider apart than those shown in de Haan's 

 figure. The oblique set of spines on the branchial regions are also 

 somewhat differently arranged. 



The chelipeds of de Haan's species in the male are described by 

 Ortmann (Zool. Jahrb., vol. vii., p. 51, 1893) as longer than the 

 cephalothorax, palm flattened, otherwise formed as in the female. 

 In the present species, represented only by the male sex, the 

 chelipeds are stouter than the next limbs and as long ; they have 

 the elongate hand and fingers quite smooth, but the two preceding 

 joints conspicuously roughened with lines of tubercles, not smooth 

 as in de Haan's female specimen. 



The conspicuous spine at the distal end of the nierus or fourth 

 joint in all the walking legs, clearly shown in de Haan's figure, and 



