Canon A. M. Norman on British Amphipoda. 129 



wood are different stages of development of the male of this 

 species. Bovallius regards fh/peria Latreillei, M.-Edvv., as 

 a distinct species ; but I agree with Sars in considering that 

 tlie differences indicated are insufficient for specific distinc- 

 tion, and are in a great measure dependent on the ages of the 

 individuals examined. Yet, further, I am unable to hold tlie 

 Jlyperia spi'nu/era, Bovallius, as entitled to specific rank. 

 The chief characters assigned are the spination of the two 

 pairs of gnathopods and the form of the uropods. Witli 

 respect to the gnathopods, T find that in young specimens of 

 //. galba the spines are sparingly developed, in middle-sized 

 individuals they become more numerous ; in large examples I 

 find them, as in ff. spinigera (Bovallius, I.e. pi. x. figs. 34-36), 

 encircling the extremities of the carpus of the gnathopods 

 and well developed at the dorsal corners. The other points 

 Bovallius especially emphasizes are the short branches of the 

 last uropods. Now in the male sex the branches of the last 

 uro))ods are always shorter than are those of the female (com- 

 ])are Sars, pi. ii. fig. ua and pi. ii. fig. 1 us) ; and it is a male 

 which is the subject of Bovallius's figures. Should other 

 authors disagree with my views in this matter, the female 

 specimens of //. galba taken by me at Birturbuy Bay and the 

 one taken off Valentia by the 'Porcupine' are, from tlie 

 character of their gnathopods, to be referred to 77. spiniqem. 

 The Cancer medusarum of Miiller's 'Prodromus'' was 

 applied by O. Fabricius, in his ' Fauna Groenlandica,' under 

 the name Oniscus medusarum^ to H. galba, and lie has been 

 followed by many authors. The Metoecus medusarum (Fabr.), 

 Kroyer and other authors, is Hyperoche tauriformis (Bate & 

 Westwood ■'^) . Lastly, Bovallius, Hansen, and Sars now 

 consider the specific name medusarum {Cancer medusarum, 

 Mliller) to belong to Hyperia spimpes of Boeck. Miiller 

 applied the specific name to the animal described by Strom, 

 and they doubtless think that weight must be attached to 

 Strom's description of the first two pairs of legs as '' hirsute 

 and fiuffy, truncated at the apex." Hyperia medusarum 

 (Miiller) thus considered, of which the H. spinipes, Boeck, 

 becomes a synonym, has not yet been found in our seas. 

 Tahtrus cyanece, Sabine, is indeed regarded as a synonym of 

 H. viedusarum [=-spinipes), but what the Hyperia cyanece. 

 of Bate and Westwood (vol. ii. p. 521) may be it seems 



* I first found this species in Shetland, and soon afterwards T. Edward 

 procured it at Banff, and sent a specimen to me and another to Bate. I 

 recorded the specimens I had seen in my Shetland report as Metoecus 

 medusarum, Kriiyer ; Bate and Westwood did not reco^^nize Edward's 

 specimen as a known form, and described it as Jlyperin tauriformis, a 

 name which now stands. 



Ann. & Mag. N. Hist. Ser. 7. Vol. v. 9 



