KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 22. N:0 7. 249 



He mentioned two species as belonging to the new genns, Parathemisto com- 

 pressa, A. Goes, and P. abyssorum, n. sp. Of the characteristics used in the diagnosis 

 those relating to the mouth-organs, and to the first two pairs of peraeopoda agree with 

 Euthemisto, and the characteristic »dorso carinato» has only specific value. 



In 1872 he repeated the Latin diagnosis, adding the following remarks, which I 

 translate: 



»This genus forms a transition between Hyperia and TItemisto, but comes nearer to the 

 latter, from which, however, it essentially differs by the last three pairs of legs being of the same 

 shape and size, while in Themisto the fifth pair are dissimilar to the others and much elongated. 

 To this genus may also belong the Hyperia oblivia, described by Spence Bate and Westwood 

 (Brit. Sessile-eyed Crust. II, p. 16), though they describe and figure the first (two) pairs of legs 

 as if they were of the same shape and not provided with a scissors-like hand in the second pair, 

 and do not mention that the dorsal side is carinated or angulated; it resembles however the follow- 

 ing species in all the other points. H. trigona, Dana, too, belongs probably to this genus, the 

 species of which thus seem to be distributed over a large area of sea.» 



In 1882 G. 0. Sars mentions the genus in his list of Norwegian Crustacea, attribut- 

 ing to it the same two species as did Boeck. 



In 1887 *) I placed the genus between Hyperiella and Euthemisto, enumerating the 

 following species, Parathemisto abyssorum, Boeck, P. oblivia, Kroeyer, P. comjjressa, 

 A. Goes, P. longipes, n. n. {= P. gracilipes, Norman), P. trigona, Dana, and P. ja- 

 ponica, n. sp.; and giving brief descriptions of all but P. longipes. 



In 1888 Th. Stebbing mentioned the species belonging to the genus, and described 

 a new species, Parathemisto pacifica. 



The first species belonging to Parathemisto recorded in the literature was thus 

 Hyperia oblivia, described in 1838 2 ) by H. Kroeyer. The next addition was made by 

 J. D. Dana, who in 1852 3 ) described Lestrigonas rubescens and Hyperia trigona; as to 

 the former species I am a little doubtful whether it really belongs to Parathemisto or 

 not; with respect to the latter I am fully convinced that it is a true Parathemisto. 

 In 1862 Spence Bate 4 ) described under the name Hyperia trigona. (Dana) a Parathe- 

 misto which is specifically distinct from Parathemisto trigona, Dana, and which is 

 recorded here as Parathemisto Batei, n. n. In 1868 Spence Bate and Westwood 5 ) 

 described and figured under the name of Hyperia oblivia, (Kroeyer), a Parathemisto, 

 which A. Merle Norman, 6 ) in 1869, recognizing its non-identity with Kroeyer's species, 

 renamed Hyperia gracilipes. In 1870 A. Boeck instituted the new species Parathemisto 

 abyssorum, which was the type for the genus Parathemisto, but which, in my opinion, 



1 ) In "Systematical list» and »Arctic and Antarctic Iiyperids». 



2 ) H. Kroeyer, ^Grenlands Amfipoder», p. 70. 



3 ) J. D. Dana, »United States Exploring Expedition. Crustacea." Vol. 2, p. 984 and 987. 



*) Spence Bate. Catalogue, of the specimens of Ampliipodous Crustacea in the collection of the Bri- 

 tish Museum, p. 297, pi. 49, fig. 4. 



5 ) Spence Bate and Westwood, A History of the British Sessile-eyed Crustacea. Vol. 2, p. 16. 



6 ) A. Merle Norman, "Shetland Final Dredging Beport». Part. 2. On the Crustacea" etc. Beport of 

 the 38 th Meeting of the British Association for the Advancement of Science; held at Norwich, 1868, p. 287. 



32 



K. Sv. Vet. Akad. Handl. Band. 22. N:o 7. 



