Cumacea: 9. Leuconidae, 1. Leucon 69 



behind the middle, and usually 2 or 3 more within the remaining space; 

 frontal lobe usually with only 1 denticle or none (instead of :•{) on each 

 side. Peduncle of uropods about equal to endopod, a little longer than 

 exopod; 2»*i joint of endopod half as long as 1^^ Adult 6 without median 

 carina. L. 9 7 mm. 



King Charles Island, lat. 78° 50' N.. depths 20—110 m. Lmcon breviremis, 

 H. J. Hansen MS., not adopted by Ohlin, as being appropriate only to young specimens. 



9. L. septemdentatus Zimmer 1902 L. s., Zimmer in: Ergeb. Hamburg. 

 Magalh.-Sammelr., v. 2 Cumac. p. 3 f. 1—5 | 1908 L. s., Zimmer in: Ergeb. Tiefsee-Exp., 

 V.8 p. 177, 178 I 1909 L. s., Zimmer in: Ergeb. Schwed. 8iidp.-Exp., v.H nr. 3 p. 5 t. 1 

 f. 6—16. 



9. Pseudorostral lobes slightly upturned; antero-lateral corners shortly 

 produced, acute. Carapace rather short, median carina variable in length 

 but not reaching beyond the middle, its teeth 5—9 in variable groups. 

 Pleon segment 5 not much longer than 4*^ telsonic segment short, little 

 produced between uropods. Antenna 1, single joint of accessory flagellum 

 equal to P* of primary. Peraeopod 1, ^^^ joint longer than 6*^ 6*^1 than 

 7th. Peraeopod 2 with full number of joints. Peraeopod 4 with 1-jointed 

 exopod on right or left limb's 2'!'^ joint, whether sometimes on both uncertain. 

 Peduncle of uropods longer than exopod, as long as endopod, of which the 

 1st joint is more than thrice as long as the '2^'^ and carries 12 spines on 

 the medial margin, the 2''^ having 4, with 2 apical, the latter very long. 

 Colour yellowish white. L, about 5 mm. 



(S. More slender than 5 . Pseudorostral lobes shorter and more blunt: 

 antero-lateral corners obtuse, not produced. Carapace without denticulate 

 carina. Flagellum of antenna 2 reaching beyond the pleon. Peraeopod 3 

 without the peculiar appendages on the 3^ joint sometimes found in c5' of this 

 genus. Peduncle of uropods rather shorter than the subequal rami, its medial 

 margin and proximally that of endopod having plumose setae intermixed 

 with the spines. L. about 4 mm. 



Fuegian archipelago, depth 6 m; Falkland Isles, depths 1 — 8 m. 



10. L. mediterraneus 0. Sars 1879 L. m., G. 0. Sars in: Arch. Naturv. 

 Kristian., v. 4 p. 25 t. 27— 29 | 1908 L. m., Zimmer in: Ergeb. Tiefsee-Exp., v.8 p. 177. 



Integument thin and flexible, squamose. Pseudorostral lobes strongly 

 upturned, triangular in 9 , shorter, sub-horizontal in d ; antero-lateral 

 corner in 9 forming a strong tooth preceded by a ianaller one, a sinus, 

 and 2 denticles, and followed by about 10 denticles on lower margin's first 

 half; in the d the corners are rounded with 2 denticles at some distance 

 from the feebler serration of the lower margin. Median carina of carapace 

 wanting in d, in 9 low, furnished with 6—8 spaced teeth, the series ending 

 just behind the middle. Pedigerous segments 2—4 with somewhat outstanding 

 side-plates. Pleon segment 5 dorsally setose behind. Telsonic segment short, 

 bluntly conical between bases of uropods. Antenna 1, 3^ joint longer than 

 1st or 2"d, flagellum 3-jointed in 9, 4-jointed in d, accessory almost imper- 

 ceptible. Antenna 2, 9 3-jointed, with 2 plumose setae on P* joint, 3'^^ joint 

 long and narrow: in d flagellum reaching nearly length of the animal, the 

 joints successively longer. Maxilliped 1 with 5 small branchial sacs. Perae- 

 opod 1, 2"'i joint unusually narrow and nearly straight. Peraeopod 2, with 

 3"^ joint lost or fused. Peduncle of uropods in 9 subequal to endopod. 

 which has 9 spines on medial margin of 1^* joint and 5 on that of the 



