KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 22. N:0 7. 151 



From the drawing given by Strom and reproduced above (p. 147), it is clear that 

 he has examined only the female of the species. Some years later or in 1776 0. F. Muller 

 gave the first scientific name Cancer medusarum to the species, though his diagnosis con- 

 sists only in the few Latin words applied to it by Strom and would have been entirely 

 insufficient for the recognition of the species if he had not referred to Strom's de- 

 scription. 



J. Chr. Fabric ius in 1779 gave (1. c. p. 326) the following diagnosis, calling the 



species Gammarus medusarum: 



»Gammarus medusarum, manibus quatuor, monodactylis, capite obtusissimo. 



Corpus paruum, incuruum, antice obtusissimum. Antenna? quatuor breuissima?, filiformes, 



simplices. Abdomen postice attenuatum. Cauda foliolis quatuor bifidis. Pedes septem parui, 



breues. Natatorii utrinque tres.» 



He mentions further (1. c. p. 354) that the he found the same species on a Gadus 

 virens. In 1781 he mentioned Gammarus medusarum and diagnosed at the same time a 

 new species, Oniscus quadricornis, with the following words: 



»Oniscus quadricornis oblongus, stylis caudalibus senis, antennis quatuor.» 



In 1787 he himself made this latter species a synonym of Gammarus medusarum 

 (1. c. p. 335). 



Latreille in 1823 gave the name Hyperia Sueurii through Desmarest in his ar- 

 ticle »Malacostraces» (1. c. p. 348), where reference is made to a copy of Strom's draw- 

 ing published in »Encyclopedie Methodique» ; no specific description nor any other drawing 

 of H. Sueurii, was given then or later and such being the case I think I am fully right 

 in taking the name Hyperia Sueurii to be a synonym for the old species of Strom and 

 Muller. 



In 1824 E= Sabine published a good description and tolerably good drawings of 

 our species under the new name Talitrus Cyaneai, (see above, p. 147, fig. 1 — 7). His 

 description runs: 



»T. capite obtusissimo, antennis subasqualibus, corpore latiore, pedibus quatuor anticis 

 inunguiculatis. 



Parasitic on the Cyanea Arctica, the individuals varying in length from two to eight-tenths 

 of an inch; colour pale yellowish red, sprinkled with innumerable minute spots of deeper red; 

 in about half the specimens, the number of which was considerable, the antenna? were equal in 

 length to the five first segments of the body; in the others they were scarcely one-fifth as long, 

 but otherwise similar; there was no other perceptible difference in the specimens. The two pair 

 of antennae are so very nearly of the same length, that it has been by no means easy to decide 

 whether the species should be considered a Gammarus or a Talitrus; those of an individual, 

 however, in which the greatest disproportion existed, have been figured (fig. 3, 4, and 5, p. 147, 

 above) for the purpose of justifying the ultimate decision; the remarkable conformation of the 

 head will doubtless be considered by many naturalists as a peculiarity requiring the establish- 

 ment of a new genus. 



Head rounded, and very obtuse; eyes extremely large, lunate, of a brownish red colour; 

 antenna? four-articulate, the second and third members very small, and the terminal setaceous, 

 flexible by annular articulations; the last joint of the superior pair is thick and fleshy at the 

 base; body of seven segments, broader and less compressed than is usual in its congeners; caudal 

 segments four exclusive of the tail itself, more attenuated than those of the body, but larger; 

 legs fourteen, the four anterior equal and similar, five-jointed, being a long compressed thigh 

 with four much shorter articulations, hirsute, and unarmed; the ten posterior legs similar and 

 equal in size, five-jointed, the thigh being long and much compressed, followed by three short 



