4 G. 0. Sårs. 



with forms previously described. For this reason they are 

 here recorded as new to science, though it is not quite beyond 

 the limits of possibility that, on a closer comparison, some 

 of them may be found to be identical with forms noticed 

 at an earlier date, but as yet so imperfectly described and 

 figured as not to admit of being recognized. 



Division Anostraca. 



Fam. Branchipodidæ. 

 Gen. Streptocephalus, Baird. 

 Remarks.^ — Of this genus, chiefly characterised by the 

 peculiar structure of the antennæ in the male, we know at 

 present of no less than 14 different species, some of which, 

 however, are as yet only imperfectly described. One of the 

 species belongs to the European fauna, 1 to the Australian, 

 1 to the Indian, 4 to the American, and 7 to the African 

 fauna. The Indian form, which will be described in detail 

 below, is easily distinguishable from any of the other known 

 species. 



Streptoceplialus dichotomus^ Baird. 



(Pl. I.) 



Streptoceplialus dichotomus, Baird, Proceed. Zool. Soc. London, 1860, 

 p. 445, PI. LXXn, fig. 2 (male). 



Specific Characters. —Body, as compared with that 

 of the other species, rather robust, with the posterior division 

 (exclusive of the caudal rami) scarcely longer than the an- 

 terior. Head in female evenly rounded, in male produced 

 in front to a short conical protuberance. Cervical segment 

 considerably produced below on each side. Segments of 

 trunk simple, uniform. Genital region in female exceeding 



