AMPHIPODA. 501 



short. It bears an accessory flagellum. Flagellum of posterior 

 antennae of the male sometimes whip-like. Basal segments of the 

 2nd-5th thoracic limbs shield-shaped and imbricated, the second 

 and third are feebly prehensile. Dwellers in mud. 



(a) Cutting edge of mandible almost simple. Lysianassa M. Edw. ; 

 Eurytenes Lilljeb. ; Anonyx Kroy. ; Opis Kroy. ; Callisoma Costa ; 

 Acidostoma Lilljeb. ; Cyphocaris Boeck ; Egidia Costa ; Glycera Hasw. 



(6) Cutting edge of the mandible toothed. Stegocephalus Kroy. ; 

 Pontoporeia Kroy. ; Bathyporeia Lindstr. ; Amaryllis and Cyproidea 

 Hasw. 



Sub-fam. 2. Phoxina. Head depressed, produced into a rostrum 

 and overlapping the bases of the anterior antennae. Terminal seg- 

 ments of the shaft of anterior antennae not short. Basal segments 

 of the 2nd to 5th thoracic legs large. Dwellers in mud. 



(a) Anterior antennae with accessory flagellum. Lepidactylis Say ; 

 Phoxus Kroy. ; Urothoe Dana ; Lilljeborgia Sp.Bate ; Phaedra Sp. 

 Bate ; Tiron Lilljeb. : Bruzelia Boeck. 



(6) Anterior antennae without an accessory flagellum. West- 

 woodilla Sp. Bate ; Monoculodes Stimps. ; Kroyera Sp. Bate ; 

 Amphilochus Sp. Bate ; Gitana Boeck ; Astyra Boeck ; Qraya 

 Sp. Bate ; Laphystius Kroyer ; Oedicerus Kroy. ; Oediceropsis 

 Lilljeb. ; Halicreion Boeck ; Pleustes Sp. Bate ; Iphimedia Rathke ; 

 Odius Lilljeb. ; Acanthonotus Owen; and (?) Epimeria Costa. 



Sub.-fam. 3. Prostomatina. Head produced into a prominent 

 rounded rostrum. Anterior antenna short, with an accessory flagel- 

 lum. Eyes very large, the mouth parts are styliform and together 

 form a conical projecting mass. Basal segments of thoracic legs 

 large. The 2nd pair terminate in a peculiarly shaped and powerful 

 chela. Only one species, Trischizostoma Raschi Boeck, is known. It 

 has been taken on the body of a dog-fish (Spinax niger) and is 

 probably parasitic. Male unknown. North Sea. 



Sub-fam. 4. Ampeliscina. Head elongated, depressed. Eyes 

 much reduced. Antennae with long flagella, but the accessory 

 flagellum is not present in the first. Basal joints of thoracic legs 

 large, setose at the margin. 4th and 5th abdominal segments not 

 distinct. Ampelisca Kroy. ; Haploops Lilljeb. ; Byblis Boeck. 



Sub.-fam. 5. Gammarina. Head high, truncated anteriorly. 

 Eyes compound. Antennae slender, the first often with an accessory 

 flagellum. Mandibular palp nearly always present. Abdominal 

 segments distinct. The sixth pair of abdominal legs either with a 

 single or a double terminal lamilla. Photis, Kroy. ; Leucothoe 

 Leach ; Stenothoe Dana ; Aspidophoreia Hasw. ; Peltocoxa Catta ; 

 Danaia Sp. Bate; (?) Callimerus Stebbing ; Pherusa, Calliope, and 

 Atylus Leach ; Helleria Norm. ; Dexamine Leach, mandibles without 

 palps ; Batea Fr. Miill. ; Brandtia Sp. Bate ; Pardalisca Kroy. ; 

 Nicippe Bruz. ; Eusirus Kroy. ; Isaea M. Edw. ; Macleayia and 

 Polycheria Hasw. ; Melita Leach, in some species one of the 3rd thoracic 

 limbs terminates in a large chela, especially developed in the male 

 (Fr. Miiller) ; Maera Leach ; Crangonyx and Gammarella Sp. Bate ; 

 Niphargus Schioedte, with rudimentary eyes, inhabits subterranean 

 waters ; Gammarus Fab. ; Pallasea Sp. Bate ; Constantia Dyb. ; 

 Melphidippa Boeck ; Amaihia Rathke ; Gammaracanthus Sp. Bate ; 

 Weyprechtia Stuxberg ; Amathillopsis Heller. 



