REPORT ON THE AMPHIPODA. 1423 



From Parathemisto japonica, Bovallius, the present species is distinguished by having 

 the fifth joint of the first perseopods longer, instead of shorter, than the fourth, and 

 pectinate, instead of smooth ; and also by having the third perseopods longer than 

 the second, and the rami of the third uropods unequal. In having the fourth perseopods 

 longer than the third or fifth, the two species are in agreement. 



Family Phrosinidjl 



In 1852 Dana placed the genera Phronima and Primno in the subfamily 

 Phronimidse, and the genera Ancliylomera, Phrosina, Themisto, in the subfamily 

 Phrosinidse. In 1862 Spence Bate placed the genera Phrosina, Primno. and Ancliy- 

 lomera in the subfamily Phrosinides. For the same three genera, as first subfamily or 

 first group of the Phronimidse, Claus in 1879, Carus in 1885, and Gerstaecker in 1886, 

 resumed the name Phrosininse. In 1887 Bovallius, without change as to the genera, 

 instituted the family Anchylorneridse, for which, I think, the name Phrosinidse should be 

 preferred by right of inheritance from the terms Phrosininse and Phrosinides, as well as in 

 deference to its derivation from the eldest of the genera. The definition which Bovallius 

 gives for the family is as follows : — 



" Head mediocre, a little tumid, not deeper than the body. Eyes large, occupying 

 the sides of the head. First pair of antennse fixed at the anterior side of the head, with 

 multiarticulate flagellum (in the male). Second pair fixed at the inferior side of the head, 

 multiarticulate (in the male), or wanting (in the female). Mandibles with palp. Epimerals 

 [side-plates] distinct. Seventh pair of pereiopoda [Fifth Perwopocls] reduced or trans- 

 formed. Peduncles of uropoda laminiform, without rami." 



It cannot, however, be stated without reserve that the mandibles have a palp, since 

 in the genus Phrosina that appendage has not yet been detected 1 in either sex, and, 

 though present in the male, it is wanting in the female, as well in Ancliylomera as in 

 Primno. In regard to Phrosina and Ancliylomera, it is scarcely accurate to say that 

 the head is not deeper than the body, although there is none of that extreme prolonga- 

 tion noticeable in Phronima and Phronimella. The eyes in this family are divided 

 each into two groups of ocelli, though the groups are contiguous on the surface. The 

 side-plates are not invariably distinct, but distinct in some segments of the perseon and 

 not in others. It would be better to 'describe the uropods as laminiform, undivided, 

 without mention of peduncles or rami. 



1 Risso's statement on the subject, quoted on the next page, can scarcely be accepted without corroboration. 



