g^g CRUSTACEA. 



Sooloo Sea; from a small island off the harbour of Soung; among 

 sea-weed floating off the shore. 



Length, four to ^.ve lines. The flagellum of the inferior antennae 

 consists of about five joints, and is but little longer than preceding 

 basal joint. The joints of the flagellum of the superior pair are about 

 three times as long as their breadth, and the setae have the same 

 length nearly; the flagellum is neatly terete, and the number of joints 

 fourteen or more. The first joint of base of inferior pair has the pro- 

 cess of the lower apex projecting beyond the extremity of the second 

 joint ; this second joint is about as long as broad. 



The finger in each hand is not longer than the transverse apical 

 margin. [The hands of the second pair may be much larger and of 

 very different characters in male individuals.] Third and fourth 

 pairs equal, long and slender. Basal joint of remaining pairs oblong, 

 and posterior margin serrulate. 



The stylets are all long, and extend equally far backward ; the last 

 or seventh joint of abdomen is short and slender in lateral view, with 

 a few setae at tip. 



It is barely possible that the 0. suluensis may be female of the 

 asper. They are alike in the very slender mandibular palpi without 

 a ciliated arrangement of hairs on the apical joint. 



Gammarus suluensis, Dana, Proc. Anier. Acad. Sci., ii. 210. 



Gammarus ALBIDUS. 



Feminse : — Epimeroe mediocres. Abdominis segment® primum secundum 

 quartumque dorso 1-2-spinosa. Antennae lmce dimidio corporis valde 

 longiores, basi breviore quam flagellum, articulo 2do paido longiore; 

 flagello fere 21-articulato, articulis oblongis, setis vix brevioribus, 

 appendice brevi, 3-articulatd ; 2dce tenuissimce, fere dimidio breviores, 

 flagello breviore quam basis, ferme S-articulato. Pedes 4 antici sub- 

 cequi, parvuli, manu oblongd, apice fere rotundatd, infra dense hirsutd; 

 manu secundd paulo longiore, digito parvulo. Pedes 6 postici sub- 

 oequi, setis numerosis, latitudine articuli 6ii paulo longioribus. 



Maris : — Pedes 2di validi, manu oblongd, basi paulo angustiore, mar- 

 ginibus fere parallelis, infra setis perbrevibus paucis, apice oblique 



