CRUSTACEA MALACOSTRACA. IV. J/ 



quite short musles are distributed with long intervals; these musles are longitudinal though somewhat oblique ; 

 each of the more distal muscles is crossed at its distal end by a distinct line on the leg indicating an articula- 

 tion, while the line is indistinct across the second and could not be seen across the proximal muscle, which 

 is situated a little beyond the base of the exopod, though near the opposite margin of the limb. As five muscles 

 are distinct, we have consequently 5 movable joints in the endopod. But the last joint is very long, 

 and its short terminal part is marked off by a moderately distinct very obliquely transverse line also seen 

 and figured by Thiele, and partly indicated by Sars in his figure of the last thoracic leg. When this terminal 

 piece is considered to be a joint we have 6 joints in the endopod, thus the same number as seems sometimes 

 to exist in Nebalia. Consequently in all 9 joints in a thoracic leg. In all other orders of Malocastraca first 

 joint, praecoxa, has disappeared, is in the Decapoda most probably a part of the pleuron bearing the pleuro- 

 branchia?; in Mysidacea the leg has 7 joints plus a terminal claw, and this claw is probably a modified joint, 

 viz. the short terminal joint observed in Paranebalia, while in Nebalia it is considerably longer. 



The natatory Legs (fig. 10 e), four pairs, have according to authors a 2-jointed sympod. But on 

 the exoskeleton of a Nebalia cleaned in caustic potash it is not difficult to see, that between the tergite and 

 the long distal joint of the sympod small chitinized plates are found, and these are very naturally interpreted 

 as belonging to two joints. Fig. 10 e shows the tergite (t), the plates (1 and 2) and the proximal part of the 

 long joint (3) of third leg from the outer side in natural position ; the lettering ma}' be sufficient for the under- 

 standing. This structure is similar to that found in abdominal legs of Cirolana, Mga and Arcturus as described 

 and figured in my 7 work on the "Ingolf" Isopoda. 



Nebalia Leach. 

 Two species have been found in the "Ingolf" area. 



1. Nebalia bipes O. Fabr. 

 (PI. IV, figs. 10 a — 10 e). 

 1780. Cancer bipes O. Fabricius, Fauna Groenlandica, p. 246, fig. 2. 

 1847. Nebalia bipes Kroyer, Naturh. Tidsskr. Ny Raakke, Bd. II, p. 436. 

 184c). — Kroyer, in Gaimard, Voy. en Scand. PI. XL, fig. 2. 



[1896. G. O. Sars, Fauna Norvegise, Bd. I, p. 9, Tab. I, Fig. 1—3; Tab. II— III, Tab. IV, 



Fig. 1—8; Tab. V. 

 1904. Thiele, Die Leptostraken, in Wiss. Ergebn. Deut. Tiefsee-Exped. Bd. VIII. 



Occurrence. Not taken by the "Ingolf", but gathered by many collectors. 

 It has been secured at many places along the coast of West Greenland. It is recorded from Saunders 

 Isl., ab. Lat. 76 1 / 2 ° N., 5 — 10 fath (Ortmann) ; Cape Dudley Digges, Lat. 76°09' N., 17 — 25 fath. (Ohlin) ; 

 Lille Karajak Fjord, Lat. 70 1 / 2 ° N. (Vanhoffen) ; Sondre Stromfjord, ab. Lat. by' 2 3 : N., 5 to 30 fath. (Ste- 

 phensen) ; Lat. 66°59' N., Long. 55°27' W., 57 fath. (Norman); Kvanefjord, ab. Lat. 6i°55' N., Bredefjord, 

 Skovfjord, Julianehaab (Lat. 6o°43' N.), in depths from 3 to 5 — 8 fath. (Stephenseu). The Museum pos- 

 sesses specimens secured by seven collectors from the following hitherto unrecorded places in West Green- 



