369 



Remark*. This new species somewhat resembles in its outward appearance 

 1. angusta, G. 0. Sars, exhibiting a similar very slender form of body. It 

 is, however, easily distinguished by the less slender anterior antennae, and still 

 more by the peculiar dilatation of the 2 middle caudal setae. 



Occurrence. Of this form at first only a single female specimen was found 

 at Lillesand. Last summer, however, I observed this species not unfrequently in 

 another locality of the south coast, viz., at Korshavn. 



Pages 97. 



For Idyopsis, G. 0. Sars. 

 Read: Idyanthe. G. 0. Sars. 



Remarks. As the generic name Idyopsis has been previously appropriated 

 in zoology, I have in my account of the Crustacea of the 2nd Fram Expedition 

 proposed the above change of name. 



Page 121. 

 Rhynchofhalestris helyolandica, (Glaus). 



Distribution. Polar Islands north of Grinnell Land (2nd Fram Expedition). 



Page 124. 

 Add the following species: 



Microthalestris littoralis, G. 0. Sars, n. sp. 



(Suppl. PI. 11, fig. 1). 



Specific Characters. Female. Very like the type species both in size 

 and general appearance, though perhaps a little less slender in form. Caudal 

 setae simple, none of them conspicuously dilated at the base. Anterior antennae 

 comparatively shorter than in the type species, but of a very similar structure. 

 Posterior antennae and oral parts almost exactly as in that species. 1st pair of 

 legs exhibiting the structure characteristic of the genus, the rami being even still 

 more slender than in the type species. Last pair of legs resembling in their 

 general shape those in M. forficula, but differing conspicuously as to the number 

 of marginal setae on the distal joint, the inner edge of this joint having only a 

 single seta, whereas in the type species 3 such setae are constantly present. 



Colour whitish, with a faint yellow tinge. 



Length of adult female 0.60 mm. 



4H Crustacea. 



