234 Liljeborgia, Idunella 



8. L. dellavallei Stebb.*) 1893 Nicip2)e pallida (part.) (err., non Gammarus 

 pallidus Bäte 1857!), A. Della Valle in: F. Fl. Neapel, i;.20 p.658 1. 1 f.l ; 1. 19 f. 35— 52. 



Rather robust. Pleon Segments 1 and 2 each produced into 3 dorsal teeth, 

 3 and 5 each into 1 tooth, segment 4 into 2 teeth. Head, rostrum small, 

 acute, slightly deflexed, lateral corners rounded. Side-plate 1 distally expanded, 

 Corners rounded. Pleon Segments 2 and 3, postero-lateral angies acute, upturned, 

 with a small siuus above. Ejes white, in 9 rather small, rounded oblong, in d 

 larger, iiTegular, approximating above. Antenna 1, 1'^* Joint longer than 2^ and 

 3*^ combined, fiagellum twice as long as peduncle, with about 20 short joints, 

 accessory flagellum with more than 12 joints. Antenna 2, ultimate Joint of 

 peduncle longer than peuultimate, rather shorter than lo-jointed flagellum. 

 Gnathopod 1, tinger with 7 teeth on proximal half. Gnathopod 2, 11 teeth 

 covering about -/s lengih of inner margin of fiinger. Peraeopods 3 — 5, 2'^ Joint 

 oval, broadly so in peraeopod 5, bind margin sti'ongiy serrate, finger small and 

 delicate. Uropod 3, rami broadly lanceolate, little longer than peduncle, Telson 

 cleft about -/s of the length, each apex seemingiy evenly bidentate. Colour 

 variable, sometimes uniformly grey, sometimes wine-red to peraeon segment 6, 

 then yellowish grey. L. 5 — 6 mm. 



Gulf of Naples. 



L. bispinosa (A. Costa) 1857 Gammarus bispinosns, A. Costa in: Mem. Acc. 

 Napoli, V. 1 p. 223 t. 3 f . 9 j 1876 Liljeborgia b., A. Boeck, Skand. Arkt. Amphip., v. 2 

 p.497 j ?1893 Gammarus loaista (part.), A. Della Valle in: F. Fl. Neapel, t;. 20 p. 660. 



L. 5 mm. 



Gulf of Naples. 



L. pugettensis (Dana) 1853 & 55 Gammarus p., J.D.Dana in: ü. S. expl. 

 Exp., v.l3u p. 957; t. 66 f. la — g\ 1876 G. j^ugetensis, Cheirocratus Qjart.), A. Boeck, 

 Skand. Arkt. Amphip., v.2 p. 395 ! 1894 G. p., C. (part.), G. O. Sars in: Crust. Norway, 

 V. l p. 523 I 1893 G. locusta (part.), A. Della Valle in: F. Fl. Neapel, 17.20 p. 760. 



Third Joint of palp of mandible seems to be longer than in other species of 

 Liljeborgia. L. 18 mm. 



Fuget Sound [Western North-America]. 



2. Gen. Idunella 0. Sars 



1894 Idunella (Sp. un.: I. aeqvicornis), G. 0. Sars, Crust. Norway, v.l p. 536 | 

 1896 Idurella, Pocock in: Zool. Kec, v.32 Crust. p. 41. 



Head, rostrum not large. Accessory flagellum of antenna 1 not very 

 large. Mouth-parts probably agreeing nearly with those of Liljeborgia (p. 230). 

 Gnathopods 1 and 2, 5*^ Joint not or very slightly produced. 



2 species. 



Synopsis of species: 



Pleon with only 1 segment dorsally dentate 1. I. aequicomis . p. 234 



Pleon with 4 segments dorsally dentate 2. I. picta . . . . p. 235 



1. I. aequicomis (O. Sars) 1876 Lilljeborgia aeqvicornis, G. O. Sars in: Arch. 

 Naturv. Kristian., v. 2 p. 255 | 1894 Idunella a., G. Ü. Sars, Crust. Norway, v. 1 p. 537 1. 190. 



Kather slender. Pleon segment 2 produced to a small dorsal tooth. Head, 

 rosti'um small, lateral corners narrowly rounded. Side-plate 1 much fexpanded, 



*) Sp. nov. After Antonio Della Valle. 



