KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 22. N:0 7. 153 



of the first pair is narrower, and the lower hinder corner is not much produced. The hand 

 (metacarpus) is elongate-ovate; the fourth joint, but especially the hand are densely set with 

 long, straight, and strong bristles. The fourth joint of the second pair is a little more produced 

 at the lower hinder corner than the first pair, but much less than in the preceding species (//. 

 Latreillei); the fourth joint and the hand of this pair also are set with long and strong bristles. 

 The peduncle of the last pair of uropoda is more than twice as long as broad, and the inner 

 ramus is somewhat longer than half the length of the peduncle. The telson is longer than broad 

 at the base, and rounded at the apex.» 



In 1887 x ) I expressed the opinion that Hyperia spihip'es, A. Boeck, was the true 

 Hyperia medusaruin, 0. F. Muller, and that Talitrus Cyaneos, Sabine, and Hyperia 

 Sueurii, Latreille, were synonyms for the same speeies. At the same time I gave 

 drawings of the animal, and of some of its details. 



The same year H. J. Hansen (see above) acknowledged the probability of my view 

 of the identity of Hyperia spinipes with H. medusarum. 



In the above list of synonyms I have not given Oniscus medusarum, 0. Fabricius, 2 ) 

 because the characteristics -»{pedes) 4 antici, pro manibus habendi, breuiores, biarticulati, 

 articulo secundo etiam compresso, margine inferiore bis inciso et ungite terminali mo- 

 bile,* make it very probable that the description of 0. Fabricius refers not to a true 

 Hyperia medusarum, 0. F. Muller, but rather to a Hyperia galba or a H. Latreillei. 

 I for my part was first 1 ) inclined to consider it as a synonym of H. galba, chiefly on 

 the ground of the shortness of the first two pairs of pera?opoda, but after the statement 

 of Hansen in 1887, (1. c. p. 225), that he himself had seen an original drawing of 0. 

 Fabricius, representing his Oniscus medusarum, which proved that it »is certainly = 

 Hyperia Latreillei, M. Edw.», I am of course bound to give it as synonymous with H. 

 Latreillei. 



Hyperia medusarum comes in general appearence nearest to H. Latreillei, but is 

 easily distinguished by the thick covering of bristles on the first two pairs of perrcopoda 

 and by the shape of the metacarpus and dactylus of the same pairs. A characteristic se- 

 parating it from the other species of the genus is the great length of the first two pairs 

 of peraeopoda, which are only a trifle shorter than the third and fourth. 



The m a 1 e. 



PI. IX, fig. 1—16. 



The body is very broad and thick, being only a little more slender than in the 

 female; the perseon is as long as the pleon and urus together. The surface of all the seg- 

 ments is smooth and even, and somewhat transversely convex. 



The head is as long as the first two peraeonal segments together, broader than 

 long, and almost as deep as it is broad. The antennal groove on the front side com- 

 mences a little below the middle and is broader than high. 



') C. Bovallius. "Arctic and Antarctic Hyperidso. Vega-Exp. Vetensk. Iakttagelser. Bd. 4, p. 561, 

 pi. 42, fig. 26—33. 



2 ) 0. Fabricius. Fauna Groenlandica, p. 258. I7S' 



20 



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



