105 
1893. Mitersttdae, Faxon, Bull. Mus. Comp. Zool. Harvard, 
Vol. XXIV., p. 206. 
1895. Hoplophoridae, Faxon, Mem. Mus. Comp. Zoél. Harvard, 
Vol. XVIIL., p. 159. 
1898. Acanthephyridae, Ortmann, in Bronn’s Thierreich, Vol. 
Vi Pt. 2; Lbielerune: 50. p. i124 
1901. Hoplophoridae, Alcock, Catal. Indian Macrura, p. 72. 
1904. Oplophoridae, M. J. Rathbun, Decap. Crust. N.W. Coast, 
N. Amer. p27. 
The choice between Miersiidae and Oplophoridae for the 
name of this family is difficult to make with any feeling of 
security. Roux in 1831 established the genus Ephyra, under a 
preoccupied name, for which Kingsley in 1879 substituted 
Miersia. In 1849 de Haan (Crustacea Japonica, decas sexta, 
p. 185) doubtfully accepted Ephyra, Roux, for a new species, 
E. compressa. Ortmann in 1894 (Proc. Ac. Phiiad., p. 400) 
makes de Haan’s Ephyra, Kingsley’s Miersta and the Paratya 
of Miers, all synonyms of Xzphocaris von Marten’s, 1872, 
adding a footnote on Ephyra, de Haan, ‘Non Ephyra Roux, 
Memoir. Salicoques, 1831, p. 24, which is identical with 
Acanthephyra, A. Milne-Edwards, and belongs to the Acanthe- 
phyridae.” But unfortunately Risso’s two species for which 
Roux founded the genus have not been again recognised, and 
Faxon accordingly proposes to leave the name Miersia in 
abeyance until they are re-discovered. On the other hand, 
the definition given by Roux rather favours the inclusion of his 
genus in this family, of which in that case it will be the earliest 
member. Should its claims be rejected, the next in order is 
Oplophorus, Milne-Edwards, 1837. On what grounds I myself 
stated in 1893 that Acanthephyrinae antedates Miersiidae I 
cannot now ascertain. This is of no importance to the present 
question, for if Acanthephyra should prove to be equivalent to 
Kingsley’s Ephyra, it would lapse as a synonym of Miersia 
(founded on the same type), and if it be distinct from Ephyra, 
Oplophorus will then rank above it as the eponymous genus of 
the family. 
Ortmann in 1898 gives the following characters :—The 
mandible is only obscurely divided and carries a palp; the 
inner lobe of the first maxilla is blunt, scarcely curved; the 
sixth and seventh joints of the second maxillipeds are laterally 
articulated (attached broadside to broadside instead of end to 
end); the chelae are normal, the fifth joint (carpus) never 
excavated ; all five pairs of trunk limbs are furnished with 
exopods. 
