Q THE VOYAGE OF H.M.S. CHALLENGER. 



Epistome.— Anterior lip (labrum). 

 Posterior lip {metastoma). 



1. Ei/es. — Pedicle; cornea; ocular papilla. 



2. A7itennul(£. ^Fcduncle ; flagella ; male appendage. 



3. Antenna;. — Basal part; terminal part (peduncle and flagellum) ; scale; 



basal spine. 



4. Mandibles. — Body of mandible ; masticatory part ; (fitting edge ; molar 



protuberance ; palp. 



5. First pair of maxilla. 1 t> i ,. i^- * i i, i ti 



^ ' -77 1 Basal part ; masticatory lobevS ; palp ; exognatli. 



6. Second pair of inaxdlcB. J 



7. Maxillipeds. — Stem (basal part and palp) ; masticatory lobes ; exopodite ; 



epipodite. 

 8-14. Limhs of the trunk or legs. — Stem (coxal, basal, ischial, meral, carpal, 

 propodal, terminal joints) ; exopod ; epipod ; gills ; incubatory 

 lamellae ; male sexual appendag»!s. 

 Incubatory pouch (marsupium). 



B. Posterior division of body or fad. — Caudal segments ; epimera ; prasanal spine. 



15-19. Caudal liiaJt.^ (plcopoda ; setiferous lamella3 ; male copulatory appen- 

 dages). 

 20. Uropoda (last pair of caudal limlxs). — Basal part : terminal plates ; 

 auditory apparatus (in Mysidae). 



« ° = 



S 1,^ "" I 21. Telson (last caudal segment). — Terminal spines ; apical incision 



Luminous globules (" accessory eyes " of earlier authors) in Euphausiidaj and 

 Gnathophausia (?). 



