62 DISCOVERY REPORTS 



Minute pleural spines on each somite. Somites 1-3 with sharp median ventral spines. 

 Telson short, with small sharp-pointed fork and no lateral spines. 



Eye nearly one-quarter length of body ; eyeball asymmetrical, greatest width a little 

 more than half total length. Legs with long vestiges of exopods. Pleopods without 

 endopods. Exopod of uropod slender, about ten times as long as wide, the bare part 

 little more than half length of setose margin. 



We have specimens of the Mastigopus of 5-9, 9-5 and 12 mm. (Fig. 55). At 9-5 mm. 

 the abdominal somites retain the pleural spines, but they are lost at 12 mm. The dorsal 

 spines are all retained up to 12 mm., and on all but somite i in a specimen of 19 mm. 

 figured by Hansen. 



Fig. 55. S. armatus. Mastigopus, 12 mm. 



Sergestes edwardsi Kroyer 



Hansen, 1922, p. 185, Mastigopus. 



Illig, 1927, p. 324, Mastigopus and Acanthosoma 2. 

 Material. This species was not taken at Bermuda. The following descriptions are 

 from specimens taken at Discovery Stations 701, 702, 703, 704, 705, 706, 708, from 

 14° 39' N, 25° 57' W to 10° 26' S, 34° 57' W. 



Description. Elaphocaris (Fig. 56 a, b). An Elaphocaris in stage 2 taken at Station 704 

 probably belongs to this species. It very closely resembles S. vigilax. Length i -00 mm. 

 Rostrum broken. 



Rostrum with two median ventral and four pairs of lateral spines at base. Lateral 

 process with ten spines including the main terminal spine. Posterior process with two 

 pairs of lateral spines. Telson arms about twice as long as wide. Dorsal organ rather large. 



Eye short, the greatest width nearly equal to the length, without papilla. Labral spine 

 not very long. 



Acanthosoma i (Fig. 56 d-f). Length 2-o-2-4i mm. Rostrum 075-0-85 mm. 

 Rostrum shorter than antennule. Supraorbital spine longer than eye. Two lateral 

 spines large, with small spinules. Posterior dorsal spine very long, bent forwards and 



