B2 



sale Lob betydelig større end den ventrale. Første 

 Par Svømmefodder med Yderkanten af den ydre 

 Gren kun forsynet med 3 Smaatænder, umiddelbart 

 ovenfor den Iste Endetorn. Halegrenene noget kor- 

 tere end de 2 bagerste Segmenter tilsammen, Far- 

 ven hvidagtig, iiden Pigmentering. Dyrets Længde 

 9 mm. 



Bemærkninger. Den her omhandlede Art staar 

 vistnok meget nær foregaaende, men er dog let 

 kj endelig fra samme ved forskjellige vel iidprægede 

 Characterer, hvoraf navnlig maa fremhæves den 

 rudimentære Beskaffenhed af Øinene og Pandepladens 

 Form og Bevæbning. Ogsaa i Bygningen af de for- 

 skjellige Kropsvedhæng vil man ved en noiere Sam- 

 menligning kunne paavise en Del mindre Difterentser 

 fra samme hos N. hipes. 



Beskrivelse. Legemets Form hos Hunnen (se 

 Pl. 1, Fig. 4) stemmer idethele temmelig nøie over- 

 ens med samme hos foregaaende Art, skjøndt den 

 maaske er noget mindre slank. Hannen er endnu 

 ubekjendt. Rygskjoldet er som hos ZV. hipes stærkt 

 sammentrj^kt og viser, seet fra Siden, en temmelig 

 regelmæssig oval Form, med den største Høide, der 

 er noget større end den halve Længde, omtent paa 

 Midten. De frie Kanter af Valvlerne er nedentil 

 jevnt buede og danner helt fortil en stærk Krum- 

 ning, inden de støder sammen ved Basis af Pande- 

 pladen. Bagtil viser de sig skraat afskaarne i Ret- 

 ningen forfra bagtil, og de nedre bagre Hjørner af 

 Rygskjoldet danner derfor, som hos foregaaende Art, 

 til hver Side en smalt afrundet Lap, der dækker 

 Siderne af Bagkroppen og næsteu rækker til Begyn- 

 delsen af Halen. Pandepladen (se Pl. IV, Fig. 9, 10) 

 er vel udviklet og af meget smal tungedannet Form, 

 temmelig stærkt hvælvet oventil, og forsynet i En- 

 den med et spidst tornformigt Fremspring, der dai> 

 ner Fortsættelsen af en langs den nedre Side lobende 

 Kjøl. Sidste Bagkropssegment har, som hos fore- 

 gaaende Art, et Par smaa afrundede Epimerer og 

 er ligesom de 3 følgende Halesegmenter grovt sag- 

 takket i den bagre Kant. Halegrenene er noget 

 kortere end de 2 foregaaende Segmenter tilsammen, 

 forøvrigt af fuldkommen samme Bygning som hos 

 foregaaende Art. 



Øinene (se Pl. IV, Fig. 9, 11) udmærker sig i 

 høi Grad ved sin ringe Størrelse og rudimentære 

 Beskaffenhed, og rager kun lidet frem fra Rygskjol- 

 det, hvorfor de let kan forbisees. De er, som hos 

 N. hipes, dækkede oventil af en skjælformig, spidst 

 udlobende Plade. Selve Øienstilken er af konisk 



recurved at the tip and furnished with long di- 

 vergent plumose bristles; the epipodite with the 

 dorsal lobe considerably larger than the ventral 

 one. First pair of swimming feet with the ex- 

 terior edge of the outer branch furnished only with 

 3 small teeth immediately above the 1st terminal 

 spine. Caudal rami somewhat shorter than the 2 

 backmost segments taken together. Colour whitish, 

 without pigmentation. Length of the animal 9 mm. 



Remarks. The species here spoken of is cer- 

 tainly very nearly allied to the preceding one, but 

 still is easily distinguishable from same by various 

 well defined characteristics, of which may especially 

 be noticed the rudimentaiy character of the eyes, and 

 the shape and armature of the frontal plate. Also 

 in the structure of the various appendages of the 

 body, we may, on a closer comparison, be able to 

 notice a number of smaller differences in the same 

 from those of N. hipes. 



Description. The shape of the body of the 

 female (see PI. I, fig. 4) agrees, on the whole, pretty 

 exactly with that of the preceding species, althoixgh 

 it is, perhaps, somewhat less slender. The male is 

 yet unknown. The carapace is, as in N. hipes, 

 strongly compressed and exhibits, viewed laterally, 

 a pretty regular, oval form; with the greatest height, 

 which is somewhat more than half the length, at 

 about the middle. The free edges of the valves are 

 evenly curved l)elow, and form, quite in front, a 

 strong curvature until they unite at the base of 

 the frontal plate. At the back they show them- 

 selves obliquely truncated in a direction from back 

 to front, and the lower posterior corners of the 

 carapace form, therefore, as in the preceding species, 

 on each side, a narrow rounded lobe which covers 

 the sides of the metasome and extends almost to the 

 commencement of the urosome. The fronlsil plate 

 (see PI. IV, figs. 9, 10) is well developed and of very 

 narrow linguiform shape, pretty strongly arched 

 above, and furnished at the extremity with a 

 pointed spiniform prominence which forms the contin- 

 uation of a carnia that rans along the lower 

 side. The last segment of the metasome has, as in 

 the preceding species, a pair of small roimded 

 epimera, and are, as well as the o succeeding caudal 

 segments, coarsely serrated on the posterior edge. 

 The caudal rami are somewhat shorter than the 

 2 preceding segments taken together, othei-wise of 

 perfectly the same structure as in the preceding 

 species. 



The eyes (see PI. IV, figs. 9, 11) distinguish 

 themselves in a high degree by their small size and 

 rudimentary character, and only project a little for- 

 ward from tlie carapace; for which reason they 

 may easily be overlooked. They are, as in N. hipes, 

 covered above with a squamiform plate running 



