Cumacea: 9. Leuconidae, 1. Leucon 



67 



p. 180 I 1879 L. nasicus, A. M. Norman iu: Ann. nat. Hist., ser. 5 «. 3 p. 70 | 1879 L. n., 

 S. I. Smith in: Tr. Connect. Ac, v. 5 p. 114 | 1884 L. n., .1. S. Schneider in: Tromse Mas. 

 Aarsh., v.l p. 54 | 1887 L. n., H. J. Hansen in: Dijmphna Udb., p. 240; and in: Vid. 

 Meddel., u 39 p. 199 | 1893 L. nasica, T. Stebbing in: Int. sci. Ser., u 74 p. 304 | 1893 

 Cuman., Apstein in: Jahresber. Comm. D. Meere, v. 6 p. 196 | 1897 Leuconoi)sis ensifer, 

 A.O.Walker in: J.Linn. Soc. London, v.26 p. 227 t. 17 f. 1— lh((^) | 1900 Leucon nasicus, 

 Gr. 0. Sars, Crust. Norway, v/6 p. 30 t. 21, 22; p. 106 L. nacica (misprint for nasica) \ 

 1900 L. nasicus, Zimmer in: Fauna arctica, v. 1 p. 417 | 1901 L. n., Ohlin in: Bih. Svenska 

 Ak., u 26 nr. 12 p. 40 | 1902 L. n., L. nasicoides (err. pro: L. nasica var.), G. S. 

 Brady in: Nat. Hist. Tr. Northumb., t). 14 p. 94 | 1908 L. nasica, Zimmer in: Ergeb. 

 Tiefsee-Exp., v. 8 p. 177 \ 1909 L. nasicus, A. M. Norman & Q. S.Brady in: Nat. Hist. Tr. 

 Northumb., ser. 2 u3ii p. 27 | 1911 L. nasica, Stappers in: Camp. arct. Orleans, Crust. 

 Malac. p. 100, L. nasicus t.4 f. 1, 6 | 1912 L. n.. Caiman in: P. U. S. Mus., i\41 p. 619. 



Fig. 34. 



L. nasica ((J) (Kroyer), peraeopod 3 

 (after Sars). 



Fig. 36. 



L. nasica (Kroyer), maxilla 1 (after 



Sars). 



Body slender and elongate. Pseudorostral lobes in 9 upturned, pro- 

 minent, obliquely truncate with the truncate edges minutely denticulate and 

 setiferous : antero-lateral corners sharply triangular preceded by a deep sinus, 

 followed for some distance by fine serration of the lower margin. In the 6 

 the lobes are shorter, little upturned, almost transversely truncate, and the 

 antero-lateral corners are obtuse with the sinus obsolete. Carapace in Q with 

 median carina serrate beyond the middle and after an interval again serrate 

 to the hind margin, but this crest is quite wanting in the adult d . _ An- 

 tenna 1, 3<i joint as long as 'I"^^, accessory flagellum minute, though 2-jointed 

 in the 6. Antenna 2 of Q with 3 plumose setae on 1^^ joint. Peraeopod 1 

 rather long, Q^^ joint not much shorter than 5*^. Peraeopod 3 in 6 with 

 2 very conspicuous unequal ensiform appendages on the ^^ joint. Peduncle 

 of uropods equal to the equal rami, 2^^ joint of endopod less than half as 

 long as the 1^*, which has on the medial margin numerous spines long and 

 short interspersed, the 2»<i joint having a graduated series of spinules followed 

 by a long apical spine and still longer plumose seta; the exopod carries numerous 



5* 



