62 Cumacea: 8. Platysynipodidae, 1. Platysympus, 9. Leuconidae 



two-thirds as long as peduncle of uropods in d, rather longer than that pro- 

 portion in 9 , the side margins very faintly serrate, the apex carrying three 

 subequal spines. Antenna 1 9, 1^* joint equalling the 2°*^ and shorter 'S^ 

 combined, flagellum 3-jointed, accessory 2-jointed; in d, 3*^ joint of peduncle 

 broader than long, flagellum 5-jointed, 1^* joint with brush of long setae, 

 accessory 3-jointed. Antenna 2 9, 1 plumose seta on each of first 3 joints, 

 4*^ joint tapering, as long as 2"*^ and 3^ combined; in 6 only just reaching 

 the pleon. Peraeopod 1, 2^^ joint nearly equal to rest of joints combined, 

 3^ very small, 4*^, 5^^ 6*^ subequal, 7*^ shorter. Peraeopod 2 narrow, 

 rather long, 2'^'^, b^^ and 6*^ joints long, the rest short, strong spines on 6*^. 

 Peraeopod 5 small, but not rudimentary. Peduncle of uropods rather longer 

 than the endopod which carries 2, 1, 1 spines on the serrate medial margin 

 of its 3 joints respectively; exopod as long as first 2 joints of the endopod. 

 Colour light yellow, with whitish band across carapace. L. 9 6 mm, 6 5-5 mm. 



Norway, to Lofoten Islands, depth 226 — ^753 m; W. of Ireland, depths 364 and 

 728 m; Mediterranean, near Capri 750 — 1100 m. 



2. P. braehyurus (Zimmer) 1907 Platyaspis brachyura, Zimmer in: Zool. 

 Anz., u 31 p. 374 | 1912 Platysympus bracJiyurus, T. Stebbing in: Ann. S. Afr. Mus., 

 V. 10 V p. 144. 



General habit as in F. typicus, but carapace not as there twice as long 

 as group of pedigerous segments, and its lateral margins obtuse, the pseudo- 

 rostrum rather longer, the first pedigerous segment shorter, the telson little 

 more than half as long as the peduncle of the uropods, with its side margins, 

 like the medial margin of the uropods, coarsely serrate. Uropods with 3, 1, 

 1 spines on the 3 joints of the endopod respectively; exopod missing. Colour 

 white, very pellucid. L. 9 about 5 mm, S unknown. 



German South-Pole Expedition, Winter Station (lat. 66O 2' S., long. 890 38' E.), 

 depth 385 m. 



9. Fam. Leuconidae 



1878 & 1879 Leuconidae, G. 0. Sars in: Arch. Naturv. Kristian., v.'d p. 466; v. 4 

 p. 22 I 1883 L., G. 0. Sars in: Forh. Selsk. Christian., nr. 18 p. 12 | 1887 X., G. O. Sars 

 in: Rep. Voy. Challenger, v. 19 pars 55 p. 8, 32 | 1893 L., T. Stebbing in: Int. sci. 

 Ser., V. 74 p. 304, 312 | 1900 L., G. 0. Sars, Crust. Norway, v. 3 p. 28 | 1907 L., Caiman 

 in: Tr. zool. See. London, v. I81 p. 31 | 1908 L., Zimmer in: Ergeb. Tiefsee-Exp., v.^- 

 p. 176 I 1909 L., Zimmer in : Ergeb. Schwed. Sudp.-Exp., v. 6 nr. 3 p. 5 1912 L., T. Stebbing 

 in: Ann. S. Afr. Mus., v. lOv p. 133, 155. 



All the pedigerous segments distinct. Telson wanting. Eye wanting. 

 First antenna with accessory flagellum small. Mandibles broad at the base, 

 spines few. Palp of first maxilla with a single filament. Branchial leaflets 

 few. Exopods on first four pairs of peraeopods in the male and the first 

 three in the female. Two pairs of pleopods in the male. Uropods with the 

 endopod two-jointed. 



4 genera. 



J First antenna not geniculate 1. Gen. Leucon 



\ First antenna geniculate — 2. 



f First antenna geniculate between 2nd and 3d joints . . 2. Gen. Eudorella 



( First antenna geniculate between 1st and 2nd joints — 3. 



{Pseudorostrum obsolete or short, vertical, truncate . . 3. Gen. Eudorellopsis. 

 Pseudorostrum obliquely upturned above the carapace 4. Gen. Pseudoleueon 



