Aristias . 49 



29. Geu. Aristias J3oeck 



1871 Aristias (Sp. un.: A. tuniidus), A. Boeck in: Forh. Selsk. Christian., 1870 

 p. 106 i 1890 & 95 J.., G. O. Sars, Crust. Norway, v.l p.47; p. 675 1893 Ä.,, A. Bella 

 Valle in: F. Fl. Neapel, i;. 20 p. 843. 



Body Short and tldck. Side-plates rather small, 1*** almost concealed, 4*^ 

 verv slightly excavate. Antenna 1 not very turgid, 2^ Joint not extremely short, 

 1^*^ Joint of flagellum rather large. Antenna 2 in 9 sliorter than antenna 1. 

 Epistome scarcely projecting, defined by a small but distinct sinus. Lower 

 lip, front lobes narrow, liind processes blunt. Mandible strong, cutting edge 

 simple, molar narrow, prominent, acuminate, palp central. Maxilla 1 with 

 5 ()]■ more setae on inner plate, outer plate very broad, palp normal. Maxilla 2 

 witli the plates divergent, inner very broad. outer much narrower. Maxillipeds, 

 inner plates small, outer large, oval, 1*** Joint of palp the largest. Gnathopod 1 

 ratlier robust, 6*^^ Joint tumid at base, tapering to an apex rather wider than 

 the base of the finger. Gnathopod 2 slender, minutely chelate. Peraeopods 3 — 5, 

 2^ Joint not greatly dilated. üropod 3, outer ramus the longer, with small 

 2^ Joint. Telson rather short, deeply cleft. 



5 species. 



Synopsis of species: 

 j Uroi)Ocl 3. inner ramus shorter than Ist joint of 

 ^ ) outer I.A. tumidus . . . . p. 49 



IUropod 3, inner ramus not shorter than Ist joint 

 of outer — 2. 



^^ I Eyes rudimentary 2. A. microps . . . . p. 49 



\ Eyes not rudimentary - - 3. 



I Telson cleft to the base 3. A. commensalis . . p. 50 



.| Telson not cleft to the base — • 4. 



f Antenna 1, accessory flagellum 5-jointed .... 4. A. neglectus . . . p. 50 



I Antenna 1, accessory flagellum 2-jointed . . . . 5. A. megalops . . . p. 51 



1. A. tumidus (Kr0yer) 1846 Anonyx t., Kreyer in: Naturh. Tidsskr., ser. 2 

 r.2 1). 16,40 1 1846 A. t., Kreyer in: Voy. Nord, Crust. t.l6 f.2 | 1887 Aristias t, H. J. 

 Hausen in: Vid. Meddel., ser. 4 v.9 p. 67 t. 2 f. 3— 3b ] 1890 A. t., G. 0. Sars, Crust. 

 Norway, v. 1 p. 49 t. 18 f. 1 | 1893 A. t., A. Della Valle in: F. Fl. Neapel, v. 20 p. 846 

 1881 Menigrates arcticMS. Orchomene? a., J.S.Schneider in: Tromse Mus. Aarsh.. v.l 

 j). 63 t. 1, 2. 



Head, lateral corners bluntly rounded, not projecting. Pleon segment 3, 

 lateral angles quadrate, margin faintly serrate. PJyes large, constricted above, 

 hlack. Antenna 1 in o, flagellum 8-jointed, accessory flagellum 4- or 5-jointed. 

 Antenna 2 in 9 , flagellum 7-jointed. Gnathopod 1 rather short and stout, 

 i)^^^ Joint with bind margin serrate, apically forming a minute palm. Peraeo- 

 pods 1 — 5, 6*^ Joint produced beneath the 7*^ to a short tooth-like process. 

 Peraeopods 3—5, 4*^^ joint expauded and decurrent. üropod 3, outer ramus 

 rather large and dilated, 2^ joint small, abruptly naiTower, inner ramus little 

 more than half as long as outer. Telson about as broad as long, narrowly 

 cleft beyond middle, not to base, with one spinule at each apex. Colour 

 greyish white. L. 8 mm. 



Arctic Ocean, Varangerfjord. Depth 110— 140 m. 



2. A. miorops 0. Sars 1895 A. m., G. Ü. Sars, Crust. Norway, v.l p.675 t.I f.2. 

 Head, lateral corners not produced, front edges nearly straight. Pleon 



segment 3, angularly produced at lateral corners (Sars, text, not figure). 

 Eyes quite rudimentary, represented each by a small patch of opaque whitish 



Das Tierreich. 2i. Lief. : T. R. R. Stebbing, Amphipoda I. 4 



