REPORT ON THE AMPHIPODA. 1063 



have thin spines, not teeth, on the outer plates of the maxillipeds, and the side-plates 

 of moderate size or large, while his Microdeutopinse have teeth on the outer plates of 

 the maxillipeds and the side-plates small, but Boeck's Photinse agree with his 

 Microdeutopinse in the armature of the maxillipcd-plates, and in point of fact some of 

 the Microdeutopinas have the side-plates well developed. In describing the family 

 Photidse, and also the subfamily Microdeutopinse, Boeck says that the accessory 

 flagellurn of the upper antennae is small or absent, whereas in reality among his 

 Microdeutopinse it is sometimes of considerable size ; if therefore the term Photidse be 

 accepted as a sufficient heading for all the three groups, it will be necessary to modify 

 the character by saying that this accessory flagellum is of variable size or absent. It 

 will also, I think, be proper to state that the fifth pair of side-plates are nearly as 

 deep as the fourth pair. 



Genus Phot'is, Kroyer, 1842. 



1S12. Photix, Kroyer, Naturb. Tidsskr., R. 1, Bd. iv. Hfte 2, p. 155. 

 1S45. „ Krpyer, Naturb. Tidsskr., R. 2, Bd. i. p. 311. 

 1819. ,, Dana, Amer. Jotirn. Sei. and Arts, ser. 2, vol. viii. No. 22. 

 1852. ,, Dana, U.S. Explor. Exped., vol. xiii. pt. ii. p. 911. 

 1862. Eisdadus, Bate and Westwood, Brit. Sess. Crust., vol. i. p. 411. 

 1865. Amphithoe, Goes, Crust, amph. maris Spetsb., p. 16. 



1869. Heiscladus, Norman, Last Report on Dredging among the Shetland Isles, p. 281. 



1870. Plwtix, Boeck, Crust, amph. bor. et arct., p. 152. 



1874. Hrisdadius, M'Intosh, Ann. and Mag. Nat. Hist., ser. 4, vol. xiv. No. 82. 



1876. Photis, Boeck, De Skand. og Arkt. Amph., p. 553. 



1877. „ Meinert, Crust. Isop. Amphip. et Decap. Daniaa, p. 111. 

 1882. „ Sars, Oversigt af Norges Crustaceer, pp. 30, 110. 



1886. „ Gerstaecker, Bronn's Klassen imd Ordnungen, Bd. v. Abth. ii. p. 506. 



1887. „ Chevreux, Catal. Amph. marins Bretagne, p. 24. 



For the original definition of the genus, see Note on Kroyer, 1842 (p. 199); for 

 Bate and Westwood's definition of Eiscladus, see Note on Bate and Westwood, 1862 

 (p. 340). In 1876 Boeck gives the following definition : — 



" Upper Antennas with the third joint of the peduncle elongate ; accessory 

 flagellum absent. 



" First GnatJwpods with a short wrist. 



" First and Second Pereeopods with the first joint not thick. 



" Third Uropods with the inner ramus minute. 



" Telson apically rounded." 



The new species, Photis macrocarpus, requires the cancelling of the second of these 

 characters. Some of those characters which Boeck places in the definition of the 

 subfamily Photinse ought perhaps to be added to the generic account, if the subfamily 

 itself is dropped. Of the mandibles he says that the spine-row consists of few (four) 



