r- 



6 Gammaridea 



proper age with marsupial plates, fringed with simple setae. The pleon 

 Segments 1 — 3 are alwa3^s distiuct; the pleopods are almost always biramous; 

 the peduncles often connected by coupling-spines (Fig. 14 p. 83) ; therami usuallj 

 tapering, many-joiuted, each Joint with a pair of plumose setae; the 1^* Joint of 

 inner ramus often having on its inner margin spines cleft at the apex. Pleon 

 Segments 4 — 6 are iisually distinct; outer ramus of the uropods sometimes 

 2-jointed; uropod 1 never absent, and always biramous; of uropods 2 and 3 

 rarely one or both obsolete, or without one or both of the rami. Telson 

 (probably) never absent, sometimes divided to the base, sometimes not divided 

 at all, and exhibiting every intermediate gradation. 



Distribution see above pag. 3. 



41 Families, 304 accepted and 9 doubtful genera, 1076 accepted species 

 and 257 doubttul. 



Synopsis of the families:*) 



- Antenna 1 (Fig. 3, 6, 9, 12), Ist Joint stout**), 

 I with accessory flagellum ; mandible 



I (Fig. 7, 8), cutting edge almost smooth***), 

 j with palp; gnathopod 2 (Fig. 10, 11), 



I 3d Joint elongate 1. Farn. Lysianassidae . . p. 8 



' These characters not combined — 2. 



/ Body (Fig. 18) plump; antenna 1 (Fig. 19) 



I with accessory flagellum; mandible 



(Fig. 17, 21) without molar, without , r. 



palp 2. Farn. Stegocephalidae . p. 88 "^ 



These characters not combined — 3. 

 Head (Fig. 25) tapering, truncate; eyes, when 

 present, externally simple, usually 4; 

 antenna 1 without accessory flagellum ; 



telson (Fig. 24) more or less cleft ... 3. Farn. Ampeliscidae . . p. 97 »' 

 These characters not combined — 4. 

 Antenna 1 (Fig^ 30 — 32) with accessory 

 flagellum; mandible with palp normal; 

 peraeopods 3 — 5 (Fig. 35 — 38) adapted 

 for burrowing by expansion of joints and 

 armature of spines and setae — 5. 

 These characters not combined — 6. 

 Peraeopod 4 not greatly longer than peraeo- 



pod 5 4. Fam. Haustoriidae . . p. 118 "^ 



Peraeopod 4 greatly longer than peraeopod 5 5. Fam. Phoxocephalidae . p. 133 w^ ) 

 Upper lip incised ; maxillipeds normal ; uropod 

 3 (Fig. 39) biramous; telson elongate, 



tapering, enjife 6. Fam. Amphilochidae . . p. 148 



These characters not combined — 7. 

 Antenna 1 without accessory flagellum; 

 maxillipeds (Fig. 44, 49, 51, 54) more or 

 less abnormal; telson entire — 8. 

 These characters not combined — 16. 

 Gnathopod 1 (Fig. 42) chelate — 9. 

 Gnathopod 1 (B^'ig. 45) not chelate — 10. 



A 



*) For some of the imperfections in this Synopsis the reader is invited to believe 

 that a more or less adequate apology could be offered, were space available for its 

 presentment. 



**) Except in Amaryllis (Fig. 5 p. 23). 

 ***) Except in Valettia and Podoprion; wanting in Kerguelenia (Fig. 2 p. 12). 



