South African Crustacea. 77 



In the first antennae the teeth of the first joint are wider apart 

 than in the other species, and the short flagellum separates from its 

 companion sooner, the common portion showing only six instead of 

 nine components ; the companion (seemingly almost complete) is 

 about four times as long. 



The mouth-organs show no differences of any apparent import- 

 ance, unless it be that the present specimen shows less expansion at 

 the base of the exopod in the first maxillipeds and less flexure of the 

 antepenultimate joint of the third pair. 



In the first peraeopods the fourth and fifth joints are here rather 

 shorter in relation to the third joint and the chela, and in the second 

 peraeopods the fifth joint is here not longer than the palm of the 

 chela. 



The total length of the specimen, a female with eggs, was 57 mm. 



Locality. East London wood, where, as long ago as April 4, 1900, 

 it was taken by Dr. J. D. F. Gilchrist, after whom I have the pleasure 

 of naming it. 



GEN. PALAEMONETES, Heller. 



1869. Palaemonetes, Heller, Zeitsch. wiss. Zool., vol. 19, p. 157. 



1890. ,, Ortmann, Zool. Jahrb., vol. 5, p. 513. 



1904. ,, Eathbun, Decap. Crust. N.W. coast of N. Amer., 



p. 30. 



1906. ,, Norman and Scott, Crust. Devon and Cornwall, 



p. 20 (with synonymy). 



1910. Kemp, Fisheries Ireland, 1908, pp. 127, 132. 



1912. Eathbun, Bull. Mus. Comp. Zool, vol. 54, 



p. 451. 



In 1899 Borradaile instituted a genus Palaemonopsis for a 

 specimen from New Britain, agreeing with Palaemonetes in the 

 absence of a mandibular palp, but differing from it in having 

 on each side of the carapace one antennal spine only. In these 

 two respects the specimen about to be described agrees with 

 Palaemonopsis, but differs so considerably from it in the first 

 antennae and the second peraeopods that it cannot safely be 

 assigned to that genus. On the other hand, with the first and 

 third peraeopods missing, I am unwilling to found upon it 

 another genus while the much-needed revision of the family 

 Palaemonidae, to which Mr. Kemp has called attention, is still 

 in abeyance. 



