TALITRUS. 15 



There can be little doubt that, under the name 

 Cancer locusta, the great Swede grouped more than 

 one species. Hence the difficulty of determining the 

 specific name entitled to priority of publication — (if 

 this difficulty exists with Linnasus, how much greater it 

 must be with earlier writers !) — a circumstance which 

 accounts for the discrepancies of opinion among later 

 authors, some attributing the name to a species of Gam- 

 maruSf and others to one of Talitrus. For our part we 

 think that Linnfeus included species of both genera, but 

 certainly Talitrus was one ; he says that it is entirely 

 of a blue colour, that the hands of the two fore pairs of 

 legs are adactyle, and hence that there are seven pairs of 

 slender feet, and that he had seen it *' ad montem Thors- 

 burg, in mari juxta Gotlandiam." On the other hand, 

 he refers to Roesel's figure of the fresh-water Gammarus, 

 and adds that the tail is trifoliated, *'intermedio subulato." 

 His disciple Fabricius has added to the confusion by 

 giving the Linnaean character of the legs, but adding that 

 the tail was furnished with bifid spines, with the locality 

 "in Europae maritimis frequentissimus dorso innatans, 

 etiam saepe in fontibus et fossis stagnantibus :" thus 

 comprising at least three species with different habits. 

 Under these circumstances, and in order to avoid the 

 confusion arising from the same specific name having 

 been also applied to the common shore species of Gam- 

 marus, it might have been correct to have retained for 

 the species of Talitrus the name of Saltatrix, given to it 

 by Klein, and adopted by Montagu and Milne-Edwards ; 

 but since Turton, in his translation of the " Systema 

 Naturae," as early as 1806, used the specific name which 

 most English authors have employed, we consider that 

 we are justified in continuing it. 



