64 üristes 



Body stout. Pleon strougK developed. Side-plates 1 — 4 in position not 

 occupying a greater leugth than side-plates 5 — 7 in position. Antenna 1 nud 2 

 calceoliferous. the fiagella manv-jointed. Antenna 1, flagellum stout, accessorv 

 tlagellum slender, Antenna 2 not much longer than antenna 1. Epistome 

 little or not at all projecting. Mandible, molar well developed, palp aftixed 

 nearly over it. the S*^ Joint elongate. Maxiila 1, inner plate with 2 plumose 

 setae, oiiter with very oblique apex, spine-teeth on apex of palp very small. 

 Maxillipeds, outer plates broad, not quite reaching apex of 2'^ Joint of palp. 

 palp rather robust, 4*'\ioint unguifonu. Gnathopod 1 imperfectly subchelate. 

 Giiathopod 2 subchehitc. Teraeopods 3 — 5, 2*^ Joint much expanded. üropod H 

 exteuding much beyond uropod 2, botli rami carrying setae on inner margin. 

 iune]' ramus longer than 1^^ Joint of outer. Telson large. twice as long as 

 broad, deeply cleft. 



2 species. 



.Synopsis of species: 



.Sidc-plate 5 smooth 1. U. gigas . . . . p. (54 



8ide-plate 5 with central boss 2. U. umbonatus . ]>. 64 



1. U. gigas Dana 1841» U., J. D. Dana in: Amer. J. Sei., ser.2 '<:.8 p. 136 i 1852 

 U. (jigas, J. D. Dana in : P. Amer. Ac, v. 2 p. 209 \ 18ÖH & 55 U. g., J. D. Dana in : U. 8. expl. 

 Exp.. v.rdu p. 917; t. 62 f. 3a— g | 1899 U. g., T. Stebbing in: Ann. nat. Hist., "ser. 7 

 /■. 4 |). 211 I 1888 U. g. -j- Trypliosa antennipotens, T. Stebbing in: Kep. Voy. Cliallenger, 

 c. 29 p. 266; p. 617 t. 6 j 1891 PsetuloUyphosa a., G. 0. Sars, Crust. Xorway, v.\ 

 p. 83 I 1893 Anonyx a. + A. ? gigas, A. Della Valle in : F. Fl. Neapel, r. 20 ]>. 827*^ 836 

 1893 Tryphosella «., J. Bonnier in: Bnll. sei. France Eelgique, t;. 24 p. 171. 



Head, lateral angles acute. Side-plate 1 narrowed below, concealing 

 the mouth-organs, 2 — 4 successively deeper, overlappiug. Pleon segment 4 

 dorsally depressed, then carinate, with upturned apex; postero-lateral angles 

 üf segment 3 produced, very broadly rounded. Eyes reuiform, seemingiy 

 large, indistinct in spirit. Antenna 1, 1^* Joint long, flagellum with 52 joiuts. 

 l"^ not very long, accessory flagellum slight, 4-jointed, shorterthanl'^^ ofprimary. 

 Antenna 2, ultimate and penultimate joints of peduncle subequal, flagellum 

 53-jointed, rather longer and thinner than in antenna 1, in both with calceoli 

 in 9 . Epistome a little prominent. ^ Lower lip, mandibular processes not 

 specially divergent. Maxilla 1 with setae ou outer margin below palp, and 

 also (accordiug to Dana) at base of its 1^* Joint. Gnathopod 1, 6*^ Joint a 

 little longer than 5*^ and nearly as broad, slightly narrowed distally, palm 

 ill-defined, 7*^1 Joint less than half length of 6*'^ Gnathopod 2, 6**' Joint more 

 than half as long as o*^\ palm transverse. Peraeopods 3 — 5, 2*^ Joint much 

 expanded, bind margin serrulate. Peraeopod 5 rather shorter than peraeopod 4. 

 Uropod 3, rami long, broadly lanceolate, subequal, carrying spines and plumose 

 setae. Telson long, narrowing a little distally, cleft ^/^ of length, with 5 lateral 

 and 2 apical spines to each lobe. L. 18 mm. 



Antarctic Ocean; Southern Indian Ocean (Heard Island, depth 274 m). 



2. U. umbonatus (O. Sars) 1882 Ichnoptis u., G. O. Sars in: Forh. Selsk. 

 Christian., nr. 18 p. 79 t. 3 f. 2 | 1891 & 95 Pseudotryphosa ümbonata, G. O. Sars, Crust. 

 Norway, v.l p. 83 t. 29 f. 2; p. 686 ] 1893 Anonyx umbonaius, A. Della Valle in: F, Fl. 

 N-apel, i-. 20 p. 825 | 1899 Uristes u., T. Stebbing in: Ann. nat. Hist., ser. 7 «.4 p.211. 



Head, lateral angles acute. Side-plate 1 narrowed below, ^^^ broader 

 than deep, with central outstanding boss or umbo. Pleon segment 3 nearly 



