H. J. HANSEN, ON SOME ANTARCTIC MALACOSTRACA. 5 



having the end of the terminal lobes subacute, not broadly 

 rounded as in Zimmer's figure of M. Hanseni. — In four 

 females with the marsupiutn half developed from lat. 54°17' 

 S. the rostrum is still shorter and broader than usual, and 

 the upturning of the margin feebly developed; the upper 

 spiniform denticle at the outer side of the antennal peduncle 

 is a little shorter than, or nearly as long as, the lower one, hut 

 the lower is always moderately short; the telson in one of these 

 specimens is scarcely 5 times as long as the terminal incision. 

 From these particulars it may be concluded that M. 

 posthon shows considerable variation in various features and 

 that mnch of this variation is individual, being foimd in 

 adult females. The specimens mentioned agree in one or 

 two features almost or completely with M. posthon, in some 

 other character frequently nearly or fully with M. similis. In 

 my opinion M. similis Zimm. must be cancelled. And a 

 future carcinologist, who has a very large material of Mysi- 

 detes from several localities at his disposal, may decide if 

 even the two other species established by Zimmer, 31. Han- 

 seni and 31. Illigi, can be considered valid. 



Mysidetes crassa H. J. H. 



Hansen, 1. c. p. 18. — In the locality a number is to 

 be altered, viz. long. 60°26' W. instead of 60°36' W. 



Neomysis patagona Zimmer. 



1907. Neomysis patagona Zimmer, Hamburger Magelh. Sammelreise, Schi- 



zopoda, p. 3, Taf., Fig. 1—17. 

 1913. Neomysis patagona H. J. Hansen, 1. c. p. 21, Pl. III, figa, 3a — 3h. 



A single subadult female from Port Albemarle, Falkland 

 Islands, was described by me (1. c); it differed from Zimmer's 

 representation in the shape of the end of rostrum (and be- 

 sides in the lobes of the maxillipeds). Three specimens, 

 among them an adult male, are now to hand; they were 

 secured at Port Famine, Straits of Magellan, 8 fath., by the 

 "Eugenie" expedition. Febr. 2, 1852, but they are unfor- 

 tunately badly preserved. The front end of rostrum agrees 

 rather well with Zimmer's figure, and fourth pleopod in the 

 male is shaped and adorned as represen ted by him. 



