ORCHESTIA. 



well aware of the variation of the form of the legs in 

 the opposite sexes of the type of the genus is fully 

 evidenced by an original drawing now in the Hopeian 

 collection at Oxford, containing highly-magnified figures 

 of the fully-developed male, of a variety of the male 

 with smaller second legs and undilated hind legs, and of 

 the female with simple legs, the sexes being indicated, 

 and the species named " Orchestia littorea" in Dr. Leach's 

 peculiar handwriting. Liljeborg had also, in his account 

 of the Crustacea collected by Dueben in Norway in 1844, 

 noticed the sexual distinctions of Orchestia littorea, de- 

 scribing the female as exhibiting the typical form of 

 Talitrus, and the male that of Orchestia, the female, in 

 fact, closely resembling the Talitrus tripudians of Kroyer 

 except in the length of the fourth and fifth pairs of legs, 

 as compared with those of the second pair. The genus 

 was previously confounded with Talitrus, and the female 

 continued so until Fr. Miiller pointed out the relative 

 distinction of the second pair of hands, and their near 

 resemblance to those of Talitrus.* Dana has more 

 recently divided the genus, distinguishing those in which 

 the female has the first pair of legs not developed into a 

 subchelate or prehensile hand (in fact, a true Talitrus] ; 

 while the male is a true Orchestia ; that is, having the first 

 pair of legs subchelate. This division, under the name 

 of Talorchestia, together with those of Talitrus and 

 Orchestia, he considers to be but subgenera of the genus 

 Orchestia. 



The genus Orchestia is perhaps the most cosmopolitan 

 amongst the Crustacea, and may likewise be classed 

 amongst the most terrestrial species of Amphipods. It has 

 been taken from the north of Europe to Cape Horn, and 



; ' Archiv. fur Naturgeschichte, 1848, p. 53. 



