252 U.S. NATIONAL MUSEUM BULLETIN 271 



4. Head with large rostrum (fig. 986), telson longer than broad and deeply 



cleft (fig. 99/) Zobracho ^ 



Head lacking rostrum, telson broader than long and scarcely cleft (fig. 99g) . 



Carangolia 



5. Inner ramus of uropod 2 absent Neohaustorius 



Inner ramus of uropod 2 present 6 



6. Maxillipedal palp article 3 weakly geniculate or clavate, outer plate of 



maxilla 2 scarcely enlarged (fig. 98d) 7 



Maxillipedal palp article 3 strongly geniculate (fig. 98/), outer plate of 

 maxilla 2 greatly enlarged (fig. 98e) 8 



7. Rami of uropod 1 expanded distally, posterodorsal border of pleonite 3 



forming a lobe overhanging urosome Pseudohaustorius 



Rami of uropod 1 not expanded distally, posterodorsal border of pleonite 3 

 not forming lobe overhanging urosome Protohaustorius 



8. Pleonal epimeron 3 with large posteroventral tooth . . . Acanthohaustorius 

 Pleonal epimeron 3 rounded posteroventrally. 



Haustorius and Parahaustorius 



9. Antenna 1 geniculate between articles 1 and 2 (fig. 99c) 10 



Antenna 1 not geniculate, or occasionally between articles 2 and 3 . . 11 



10. Gnathopod 2 lacking dactyl (fig. lOOi) Bathyporeia 



Gnathopod 2 bearing dactyl Amphiporeia 



11. Coxa 1 vestigial, less than one fourth as long as coxa 3 12 



Coxa 1 not vestigial, at least half as long as coxa 3 13 



12. Coxa 2 vestigial, less than one fourth as long as coxa 3 . . Urohaustorius 

 Coxa 2 not vestigial, almost as large as coxa 3 Cardenio 



13. Coxa 2 obtusely pointed below (fig. 97a) 14 



Coxa 2 rounded or quadrate below (fig. 100a) 15 



14. Telson split nearly its full length Zobracho 



Telson split one third its length Priscillina 



15. Gnathopods chelate (fig. lOOd) Platyischnopus 



Gnathopods subchelate or simple 16 



16. Inner ramus of uropod 3 scale-like, half as long as outer ramus (fig. 100m). 



Carangolia 

 Inner ramus of uropod 3 subequal to outer 17 



17. Mandibular palp large, borne on basal process (like fig. ISO^r), article 3 



clavate, molar of medium size, ridged Phoxocephalopsis 



Mandibular palp small, directly attached to mandibular body, article 3 

 linear, molar large or medium, smooth 18 



18. Outer ramus of uropod 3 uniarticulate 19 



Outer ramus of lu-opod 3 biarticulate 20 



19. Accessory flagellum present, usually 2-articulate; pereopod 5 shorter and of 



different structure than pereopod 4 Pontoporeia 



Accessory flagellum absent; pereopod 5 similar to pereopod 4. 



Zaramilla (Eusiridae) 



20. Article 4 of pereopod 4 not expanded, article 2 of pereopod 5 not greatly 



produced downward Urothoe 



Article 4 of pereopod 4 expanded, article 2 of pereopod 5 greatly produced 

 downward Urothoides 



-' Zobracho .T. L. Bnrnaid (1961). Note thu tlip liasal article o( the maxillipedal palp was not inked on the 

 oiipinal diawiiif;; tlic iialp has four articles. 



