NjcholI;S — // Krir Blind Fre-diiralrr Amphipod. 
i i 
Crangomjx, Varacrangonijx^ Et(cr(tiif/n)iyx, and Nconiphargiis* In 
the genus ('i'anfp)niix arc? plared a number of speides (mostly from 
wells and spi'ings in North America), in whicli the telson may l>e 
either entire or (deft in vai-ying (h'gree. In all of tliese, however, 
the inner ramus of tlie tliird uro])od has disajiiK'ared. In 
Eucrangonyx (habitat and distribution agreeing with that of 
Crango)iyx) with one of tiie s]>ecies of which {K. rejdovskyi) the 
Western Austi’alian form sliows many ])oints of agreement, the 
genus is defined as possessed of an enmrginate telson. Had the 
telson in this genus l>een variable, as it is in Cra)ig<>)iyx, I should 
have been inclined to la f(.u' tlu' m'w s'pecii's to it. To the N(oc 
Zealand form, 7\ir(icraiigoiiyx comparfu.s (Chilton), also, P. fonti- 
ludis, comes very near inasmuch as although both rami of the pleo- 
pods are retained in the latter, there is a marked difference in the 
degree of develoimient of the two rami, one apparently undergoing 
reti'ogressioii. In both ilie tcdsoii is entire. The mouth ]>arts, too, 
are more nearly alike, the inner plate of maxilla 1 being small and 
with but few setae (2 and 1 respectively), whereas in Crangonyx 
and Kucrangouyx the inner ]>late has numerous (4 — d) setae. In 
the condition of the mouth ]>aits, foiitiiialis a])]>roaches, also, to 
Nconiphargus^ but in this genus the telson is (deft and tlie third 
uropod elongated. 
In the charart('r of the setae it is inttu'csting to note that the 
notched seta with tlie ciliuin is found not only in Crangonyx and 
Protocrangonyx, but also in Ncoinpliargu.s. In this genus I find it in a 
blind Victorian species {N. obrirni^ lt)2(i), and also in another blind 
form, N. tvcstralis (diilton (192d). AVhat may readily lie a tran- 
sitional condition in the evolution of this tyj)e of seta is figured Ity 
Sayce in his account of Niphargu.s pulrlicll ns (li)OO, PI. Hi, Pig. 12), 
where a stout ])lumose seta, occurring near the base of a pleojaul 
ramus, is shown with one branch closely comparable in position and 
size to the Cmngoiiyx cilium. U])on: the dactyl of tlu‘ peraeo])ods 
(PL VIll. Pig. 8) there is in P. fon-Uiuilis a siugh' stiff seta in the 
position occupied in Neoniphargus by the characteristic, well-devel- 
oped plumose seta. 
*A11 of these genera are, however, represented almost entirely by 
forms which have taken to a subterranean inode of life, and 
while tiie resemblances may well be ex]dai\ied by a common 
ancestry, it is possible that many of their ('ommon features may 
be due to convergence resulting from adaptation to a similar 
manner of life. 
List of References. 
1893, Thomson, G. AL, P.P.R., Tas., 1893. 
1900, Sayce, 0. A., P.R.S., Vic., 1900. 
