210 A HISTORY OF RECENT CRUSTACEA 
species that belong to Southern Brazil; Paranephrops, 
White, 1831, is found only in New Zealand and (possibly) 
Fiji, while even within the limits of New Zealand its two 
species, planifrons and zealandicus, are found by Mr. Chilton 
to have distinct and separate ranges; Astacopsis, Huxley, 
1878, and Engeus, Erichson, 1846, belong to Australia 
and ‘lasmania, while Cheeraps, Erichson, 1846, belongs to 
Australia alone. Chceraps was instituted only as a sub- 
genus by Erichson, and by Mr. Haswell it is united with 
Astacopsis. Spence Bate, in remarking upon the peculi- 
arities of distribution here set forth, speaks of ‘ the several 
genera being adapted each to its own locality, no two 
genera being known to exist in one habitat,’ but to support 
this statement he assigns Astacopsis to Australia, Hngeus 
to l'asmania, and Cheraps to Van Diemen’s Land, intend- 
ing perhaps a just reproach to those who altered the name 
of Van Diemen’s Land into Tasmania. In fact the small 
burrowing Hngceus may be peculiar to that island, and, 
if not, it is separated by rather subtle distinctions from 
Astacopsis, so that the three genera in question form a very 
united group, and it is singular that, while they agree 
together in their branchial arrangement, they differ in that 
respect from all the other genera in the two families under 
discussion. The unnamed ‘ Australian Crayfish’ of Huxley, 
which sometimes reaches a length of twenty inches, is pro- 
nounced by Mr. Haswell to be Astacopsis serratus (Shaw). 
In Paranephrops zealandicus, Mr. Wood-Mason has ob- 
served that the young are specially fitted for attachment 
under the pleon of the mother. The specimens examined 
were under a third of an inch in length. The two hind- 
most pairs of legs have the sixth joint ‘provided at its 
extremity with a strongly hooked, exceedingly acute, 
movable claw, and on the lower edge at the end with six 
or seven sharp spines, against which the claw folds, and 
thus forms a very efficient prehensile arrangement.’ 
