(PI. II., teL.). Tkese segments decrease rapidly iu size 

 from before backwards, and tlieir terga overlap to a great 

 extent, allowing the abdomen to be bent right forward 

 under the thorax. The terga of the first three abdominal 

 segments or metasome are produced into large epimeral 

 plates (PI. I., hg. lo and PI. II., epini. p.2), which increase 

 in size from before backwards and are pointed at the 

 infero-posteal corners, though the last pair are less drawn 

 out in G. index than in other species of Gammants (PI. I., 

 kg. 13, epini. p. 2). In G. locusta, the last pair of 

 epimeral plates of the metasome are considerably pro- 

 duced at the lateral corners, and bear setae along the 

 posterior edge. Each segment of the metasome bears a 

 pair of pleopods or swimming feet, consisting of a single, 

 stout, elongated protopodite, bearing two similar, many- 

 jointed rami (endopodite and exopodite) furnished with 

 long, plumose setae (PI. I., ^g. 12). The last three body 

 segments or urosome usually move as one, slipping 

 between the last pair of epimeral plates when flexed, and 

 forming a powerful propelling organ. They bear the uro- 

 pods (PL II., uro. 1, 2, 3), the last pair being the largest 

 (PI. II., uro. 3), and have no epimeral plates. In G. pulex, 

 the posterior edge of each tergum bears two small dorsal 

 spines and a single lateral one; iu G. locusta, eack bears a 

 small dorsal projection armed witk from tkree to five 

 spines, and kaving from tkree to four spinules on eack 

 side. Tke telson (PI. I., fig. 11, and PI. II., tel.) is very 

 small and consists of a basal joint witk two rami, eack 

 bearing two apical spines and one lateral one in G. jmlex; 

 in G. locusta eack ramus bears tkree apical spines, and 

 two groups of lateral ones, tke proximal group consisting 

 of tkree, tke more distal group of two spines. Tke anus 

 opens below tke telson and above tke last pair of uropods, 

 not below tke latter, as Sars (19) figures for G. neglectus. 



