8 Gammaridea, Lysianassidae 



vir 



f Rostrum weak 22. Farn. Calliopiidae . . . p. 285 



IRostruin well marked — 26. 



{Side-plates 1 — 4 rounded; antenna 1 longer ^ß^ 



than antenna 2 23. Fam. Pleustidae . . . . p. 309 *^ 

 Side-plates 1 — 4 angular; antenna 1 shorter >ijß- 



than antenna 2 24. Fam. Paramphithoidae p. 320 



i Pleon Segments 5 and 6 coalesced .... 25. Fam. Atylidae . . . . p. 327 

 27 ^ Pleon segments 5 and 6 not coalesced 

 l (Fig. 80) — 28. 



{Lower lip, inner plates rather large; uropod 

 3 greatly elongate 26. Fam. Melphidippidae . p. 334 

 Lower lip, inner plates small or wanting; 

 uropod 3 (Fig. 81) not greatly elongate — - 29. j^ 



{Grnathopods 1 and 2, hands powerful (Fig. 79) 27. Fam. Eusiridae . . . . p. 338 ^ 

 Gnathopod 1 without band 28. Fam. Bateidae ....]). 355 *^ . p, 

 Gnathopods 1 and 2, hands not powerful . 29. Fam. Pontogeneiidae . p. 356 ^^ 

 j Uropod 3, both rami well developed ... 31. Fam. Dexaminidae . . p. 514 *^ 

 \ Uropod 3, one ramus wanting or very small 32. Fam. Talitridae . . . p. 523 "^ 

 f Imperfectly developed eyescoveringthehead 41. Fam. Hyperiopsidae . p. 714 

 \ Eyes, when present, not abnormal — 32. 

 I Uropods 2 and 3 (Fig. 103, 118) developed — 33. 

 32 l Uropods 2 and 3 (Fig. 121, 127), one or 



l other wanting or rudimentary .... 40. Fam. Podoceridae . . . p. 694 »-^ 

 J Pleon (Fig. 110) compressed — 34. 

 \ Pleon(Fig. 115, 118), asarule,depressed — 38. 

 J Uropod 3 (Fig. 103) not uncinate — 35. 

 \ Uropod 3 (Fig. 110) uncinate — 37. 

 Gnathopod 1 (Fig. 101) larger than gnatho- 

 pod 2 33. Fam. Aoridae p. 585 ^ 



\ Gnathopod 1 (Fig. 104, 105) not larger than 



35 



I uru 



gnathopod 2 — 36. 



f Peraeopods 1 — 5 not subchelate 34. Fam. Photidae . . . . p. 603 ^^ 



\ Peraeopods 1 — 5 subchelate 35. Fam. Isaeidae . . . . p. 630 



j Lower lip with principal lobes notched . . 36. Fam. Ampithoidae . . p. 631*^ - 



I Lower lip with principal lobes not notched 37. Fam. Jassidae . . . . p. 647 *H^ 



{Antenna 2 (Fig. 116, 117), flagellum not 



spatulate 38. Fam. Corophüdae . . . p. 662*^"^" 



Antenna 2 (Fig. 119), flagellum spatulate . 39. Fam. Cheluridae . . . p. 693 • 



1. Fam. Lysianassidae 



1849 Subfam. Lysianassinae, J. D. Dana in: Amer. .1. Sei., ser. 2 t). 8 p. 136 i 1856 

 I/ysianassides, Bäte (& Westwood) in: Rep. Brit. Ass., Meet. 25 p. 21 | 18ö7 Lysiassides, 

 Bäte in: Ann. nat. Hist., ser. 2 ». 20 p. 524 j 1857 Subfam. Lisianassini, A. Co.sta in: 

 Mem. Acc. Napoli, «.1 j). 173 | 1865 Subfam. Lysianassina -\- Subfam. Trischizostomatina, 

 "W.Lilljeborg in: N. Acta Soc. Upsal., ser. 3 v.6 nr. 1 p. 18 \ 1872 Prostomatidae -\- 

 Subfam. Lysianassinae, A. Boeck, Skand. Arkt. Amphip., v.\ p. 94; p. 112 I 1874 Lysia- 

 nassidae, Buchholz in: Zweite D. Xordpolarf., v.2 p. 299 | 1888 L. -{- Valettidae, T. 

 Stebbing in : Rep. Voy. Challenger, v. 29 p. 606, 723 | 1890 L., G. O. Sars, Crust. Xorway, 

 v.l p.28 I 1893 Lisianassidi, A. Della Valle in: F. Fl. Neapel, ?;. 20 p. 769. 



Of side-plates 1 — 5 (Fig. 3, 4, 6) one or more deep (except in Valettia). 

 Eyes (Fig. 3, 6) usually large, paired, rarely reduced each to a Single lens 

 (Hippomedon holbölli, Acidostoma sp.), sometimes degraded or absent (triple 

 in Hirondellea). Antenna 1 (Fig. 5, 9, 12) not longer than antenna 2. the 

 1^* Joint tumid (except in Amaryllis, Fig. 5j. Accessory flagellum always 

 present (except in Lepidepecreum longicorne, p. 80). Flagellum of antenna 2 



