36 CRUSTACEA MAI.ACOSTRACA. III. 



from the base a single pair of large spines are found on the ventral surface, and in the largest male 

 besides two or three spines; the lamella is about three times as long as broad, tapering from consider- 

 ably before to a little beyond the middle and then with the margins nearly parallel to near the end, 

 which is a little narrower; the terminal margin of each pleopod is deeply concave, as the pleopod 

 terminates in a rounded setiferous lobe, while its outer part is produced into a rather large, triangular, 

 acute jjrocess directed backwards. 



Length of the largest specimen, a female without marsupium from the Upernivik district, 

 3-4 mm.; a male from the same place is 3-2 mm. long. An ovigerous female from Egedesminde is 27 mm. 



Remarks. In the list of the Danish Isopoda, etc. (1910) I had referred the specimens of this 

 species to M. Boeckii, but after the discovery of the value of the shape of the median lamella of the 

 male operculum I saw that it is in reality a new species, though none of the characters found in other 

 organs are very valuable, the best being the conspicuously feebler armature with spines on the abdomen. 

 The opercular lamella differs sharply from those in the six other species by the shape of its end. 



Occurrence. Not taken by the "Ingolf". 



At West Greenland this species has been taken at three places. In the Upernivik district, 

 Lat. ab. /2°47' N., 3 spec, were secured by Commodore Ryder; at Egedesminde, Lat. 68°42' N., 1 spec, by 

 Mag. Transtedt. In a bottle labelled: Godthaab (Lat. 64°n' N.) c. 50 fath., Holboll, I found 6 specimens 

 of this species among 9 specimens of the real M. Fabricii. and they must be considered as determined 

 by Kroyer. 



At East Greenland it has been secured at four places, viz.: at Angmagsalik, Lat. 65°3o' N., 2 

 spec, by Mag. Kruuse; at Tasiusak, Lat. 67°37' N., 3—5 fath., 5 spec, by the 1st Amdrup Exp.; at Lat. 

 67°4' N., at the beach, 2 spec, by the Ilnd Amdrup Exp.; finally at Danmarks-0, Lat. 70°27' N., 3 spec. 

 by the Ryder Exp. 



19. Munna Hanseni Stappers. 

 (PI. Ill, figs. 3 a- 3 h.) 

 191 1. M11 una Hanseni Stappers, Crust. Malacost, in Due d'Orleans, Camp. Arctique de 1907, p. 91. 



Description. General aspect of body and limbs nearly as in M. Boeckii, — Eye-stalks and 

 eyes together (fig. 3 a, 3 c, 3 d, 3 e) conspicuously smaller than in M. Boeckii, generally forming a some- 

 what conical or at the end broadly rounded protuberance which varies in shape, being from a little 

 longer to conspicuously shorter than broad; the eyes are very reduced, containing only some few facets, 

 or sometimes scarcely any facet can be perceived; the inner contents of the eyes are light brownish 

 and much removed from the cornea. -- The antennulae (figs. 3 a, 3 c and 3 d) always consist of 8 joints, 

 but they vary considerably in length, as in specimens from the "Ingolf" Stat. 44 they are only some- 

 what more than half as long as the distance between the eyes (fig. 3 a), while in the specimen from 

 Stat. 81 they are even a little longer than that distance (fig. 3 d), and in the specimens from the two 

 other stations they are almost as long; such long antennulae are, besides, more slender than in spec- 

 imens from Stat. 44. First peduncular joint is moderately thickened, longer than broad; second joint 

 somewhat or considerably longer than the first; the 5-jointed flagellum with the three intermediate 

 joints more or less long, but varying much as to their relative length; terminal joint very short. 



