276 



Tiron, Argissa 



peraeopod 5. Uropods 1 and 2, outer ramus tlie sborter; uropod 3. rami 

 long, lanceolate. subequal, outer with sraall 2'^ Joint. Telsou narrow, very 

 long, deeply cleft. 



1 species. 



1. T. acanthurus Lillj. 1865 T. a., W. Lilljeboi-f? in: N. Acta Soc. üpsal., ser. 3 

 r.6 nr. 1 p. 19 | 1876 T. a., A. Boepk, Skand. Arkt. Ainphip., «.2 p. 475 t. 9 f. 8; t. 13 

 f. 1 I 1893 T. a., G. 0. Sars, Crust. Norway, v. 1 p. 399 t. 140 1 1893 T. a., A. Della 

 Valle in: E. Fl. Neapel, u20 p.693 t.60 f. 1 I 1866 Syrrhoef?] bicuspis, Goes in: Öfv. Ak. 

 Förh., V.22 p. 528 t. 40 f. 26 ] 1868 Tessarops hastata, A. ]\I. Norman in: Ann. nat. 

 Hist., ser. 4 v. 2 p. 412 t. 22 f. 4—7. 



Pieon Segments 1 — 3 dorsally serrate, with about 10 teetli. segments4 — 6 

 dorsally produced to conieally poiuted proccss, sraallest on segment 6. Head. 

 rostrum reaching about middle of 1^* Joint of antenna 1, lateral corners nearly 

 quadrate. Side-plates 1 — 3 rather narrow, distally crenulate, setose, 4*^ sliglitly 

 emarginate, obtusely triangulär below, 5*^i and 6*^, bind lobe deep, rounded. 

 Pleon segraent 3, postero-lateral angles rainutely produced, Upper eyes rounded, 

 dark red. Antenna 1 in 9 , 1** Joint nearly ^as long as 2*^^ and 3^ combined, 

 flagellura longer tban peduncle, 10-jointed, accessory flagellum half as long, 

 5-jointed. Antenna 2 in y rauch longer, ultiinate Joint of peduncle shorter than 

 penultimate, flagellum half as long as peduncle, 9-jointed. Antenna 1 in d, 

 P* Joint longer than 2** and 3*^ combined. flagellum raore than twice as long as 

 peduncle. l'^'^ Joint very long, densely fringed. Antenna 2 in ö, flagellum longcr 

 than peduncle, 1 5-jointed. Gnathopods 1 and 2, 5*'^ Joint distally narrowed, 

 more than twice as long as 6*\ the small flnger 2-jointed. Peraeopods 1 

 and 2, 4^^ Joint longer than 5*^ or 6*i\ flnger sraall. l'eraeopods 3 — 5 

 rauch stouter. 4*'' Joint rauch larger than 6*^, especially in the 5*^ pair. 

 Uropod 3 reaching rauch beyond uropods 1 and 2, spinules and setae on 

 the rarai more developed in ö than in 9 . Telson cleft nearly to the base, 

 gradually tapering. apices acute, contiguous. Colour dark reddish brown, 

 antennae banded with brown. L. Q 8, d 9 rani. 



Arctic Ocean. North- Atlantic, North-Sea and Skagorrak (Greenland, Norway, 

 Great Britain); Kattegat. Deptli 38— 113 m. 



3. Gen. Argissa Boeck 



1871 Argissa (Sp. nn. : A. typica), A. Boeck in: Forli. Selsk. Christian., 1870 

 p. 125 I 1891 A., G. 0. Sars, Crust. Norway, v.l p. 140 \ 1893 A., A. Della Valle in: 



F. Fl. Neapel, i;.20 p.686 | 1890 Chi- 

 maeropsis (Sp. un.: C. danicä) (non 

 Zittel 1887, Pisces!), Meinert in: Udb. 

 Hauchs, V. 3 ]>. 167. 



Body (Fig. 70) conipressed. 

 Head not or little rostrate. Side- 

 plates decreasing frora 1*** to 3'^. 

 4*^ large, shield-like, little ex- 

 cavate. Antenna 1 shorter than 

 antenna 2, accessory flagellura 

 sraall, with 2 joints, 2*^ miuute. 

 No calceoli. Upper lip slightly 

 notched. Mandible, cuttiug edge 

 and accessory plate dentate, raany spines in spine-row, raolar strong, palp 

 slight, 3^ Joint longer tliau 2'^. Maxillal, inner plate with 2 or 3 setae, 2^ Joint 



Fig. 70. A. haidatipes, 5 . 

 Lateral view. [After G-. 0. Sars.] 



