26 Annals of the South African Museum. 



uses the median dentate crest of the carapace to distinguish 

 this genus from Penaeus, Parapenaeus, and Xiphopeneus. In 

 1911 de Man enumerates twenty named species, a named 

 variety, and two unnamed species as belonging to the genus. 

 Between some of them the distinguishing characters seem to 

 be of slight importance. 



EUSICYONIA LONGICAUDA (Eathbun). 

 Plate LXXIII. 



1906. Sicyonia longicauda, Eathbun, Bull. U.S. Fish. Comm., 1903, 



p. 908, pi. 20, fig. 6. 



1911. ,, de Man, Siboga Exp., vol. 39a, pp. 11, 



113. 



The South African specimens are in clear agreement with 

 the figure and the characters supplied by Miss Eathbun, 

 except in an unimportant detail. The rostrum is apically 

 bidentate, the upper tooth projecting a little beyond the lower 

 one. The earlier description gives to the rostrum " tip oblique 

 truncate, with three projections, a tooth between two spines." 

 In describing the telson as having " a pair of lateral spines 

 not far from the tip," it is not unlikely that Miss Eathbun 

 refers to the pair of unjointed processes which occupy the 

 position in question in our specimens. There are three pairs 

 of microscopic spines spaced higher up, and much of the 

 telson is fringed with plumose setae. In the first antennae 

 the lower spine-tooth of the first joint does not nearly reach 

 the base of the apical tooth. In the first maxilla the outer 

 plate or palp has two setae at the inner corner of its apex, and 

 within the outer margin has a row of seven spines on the 

 surface. The second maxilla has three very small stumpy 

 spines about the apex. The first pleopod shows a little wart- 

 like piece apparently distinct from the peduncle by the side of 

 the single ramus. 



The largest of the South African specimens was about 

 56 mm. long, the carapace with rostrum measuring 19'5 mm., 

 the fifth pleon segment 5 mm., the sixth 8 mm., the telson 

 8'5 mm. The uropods were slightly shorter than the telson, 

 both branches with rounded apices. 



Locality. Buffalo Eiver N. 15 miles (East London, Cape 

 Colony) ; depth 310 fathoms. A 1219. 



