KONGL. SV. VET. AKADEMIENS HANULINGAR. BAND. 22. NIO 7. 



307 



Euthemisto bispinosa, A. BOECK. 



1878. Lestrhjonus spinidorsalis, SPENCE BATE. 



Hyperia spinidorsa lis, 



C. Bovallius. 1887 . "Systematical list of the Amphi- 



poda Hyperiidea». Bih. t. K. 

 Sv. Vet. Ak. Handl. Bd. 11. 

 N:o 16, p. 22. 

 » 1887 . "Arctic and Antarctic Hyperids». 



Vega-Exp. Vetensk. Iakttagel- 

 ser. Bd. 4, p. 569, pi. 46, 

 fig. 97—103. 



Th. Stebbing. 1888. "Report on theAmphipoda». Voy. 



of H. M. S. Challenger. Zoo- 

 logy. Vol. 29, p. 1408. 



— »Two new Crustacea from the 



coast of Aberdeen". Ann. and 

 Mag. of Nat. Hist. 5 th Ser., 

 Vol. 3, p. 411, fig. 2. 



— 1878. "On the Willemoesia Group of 



Crustacea". Ann. and Mag. of 

 Nat. Hist. 5 th Ser. Vol. 3, 

 p. 489. 



After having compared many individuals of both sexes and different ages of the 

 two supposed species Themisto compressa and Th. bispinosa, I am convinced that they 

 are one and the same species, as Hansen also suggested in 1888. The species must 

 therefore have the older name given by Goes in 1865, and it is here recorded as Euthe- 

 misto compressa, Goes. 



The original diagnosis runs: 



T. compressa n., carinata segmentum septimum sajpe etiara sextura et octavum margine 

 postico in spinulam productum dorsalem in juvenibus exiguam, in adulto facile conspicuam; an- 

 tennae a 71 flagello multiarticulato, tenuissimo, valde elongato ut in Hyperiis omnino.» 



The drawings which accompany his description are however somewhat erroneous, 

 and suggest the idea that the fifth pair of peraeopoda are built exactly as the sixth pair, 

 and are quite as long, the animal thus being a Parathemisto and not an Euthemisto; 

 but after examining his type-specimens, now preserved in the Natural History Museum 

 at Stockholm, I find that this is only due to a misconception of the draughtsman, as in 

 all the specimens labelled by Goes's hand, the carpus of the fifth pair is distinctly longer 

 and broader than in the sixth pair, and that in only one single specimen the fifth pair 

 do not reach distinctly beyond the apex of the sixth. 



A. Boeck in 1870 gave the following diagnosis of Parathemisto compressa: 



»Segmentum trunci ultimum et segmenta postabdominis dno anteriora carina spinas retro— 

 versas formanti. Pedes 3tii et 4ti paris articulo 4to magno, elongato-ovali. Pedes 5ti paris arti- 

 culo 4to duplo longiore qvam articulo 3tio.» 



And of Themisto bispinosa he gave the following diagnosis: 



»Corpus compressum, segmentum trunci 6tum et 7mum in medio margine posteriore in 

 spinas producta. Pedes 3tii et 4ti paris articulo 4to oblongo. Pedes trium parium ultimorum 



