414 
ZOOLOGY OF THE FAR EAST. 
Zimmer has rightly referred Cryptomysis lamellicaitda, Hansen, to the genus 
Anisomysis and called attention to its very close resemblance to the present species. 
The only striking point of difference is in the number of curious processes on the 
inner margin of the second joint of the mandibular palp, 7-8 in A. ijimai and 13 in 
the only known specimens of .-1. lamellicauda. At first I was inclined to consider 
these species as synonymous but I think perhaps it would be well to await the 
the examination of further specimens from the type locality of A. lamellicauda, 
especially of male specimens, before deciding this point. 
Zimmer, whose recent work on the Mysidacea, has added very largely to our 
knowledge of the group and whose attempt to systematise the species of the tribe 
Mysini is of the greatest value, refers both the genera Cryptomysis, Hansen, and 
Kreagromysis, lUig, to the synonymy of Anisomysis, and the latter genus, therefore, 
now includes the following species : — 
A . laticauda, Hansen ; 
A . ijimai, Nakazawa ; 
A. lamellicauda, Hansen; 
A . mixta, Nakazawa ; 
A. hifurcata, Tattersall {= Kreagromysis megalops, Illig) ; 
A. australis, Zimmer. 
These species agree fundam_entally with one ^mother in the form and characters 
of the pleopods of the male (the male of A . lamellicauda is unknown, but in view of 
the very close affinity of this species with A. ijimai there can be little doubt that 
it also has male pleopods like the other species). In view of this fundamental 
agreement among this group of species, Zimmer naturally raises the question of the 
value of the form of the telson as a character of generic importance. In the group 
generally, the form of the telson has been very largely used as a generic character in 
the past, and in the main, rightly so. But, for the present, it looks very much as if 
Anisomysis was a genus characterised by great variability in the shape of the telson, 
with a greater degree of constancy in the other characters. As Zimmer points out, 
if the shape of the telson is a character of generic importance, the above six species 
will fall into four genera, viz.: — 
Anisomysis A. laticauda. 
Cryptomysis A. ijimai, A. lamellicauda. 
Kreagromysis A. hifurcata. 
A new genus A . mixta, A . australis. 
Future research may demonstrate the existence of groups of species which fall 
naturally into these genera and justify their separation, but in the present extent of 
our knowledge Zimmer' s arrangement is the more acceptable. 
