74 . 
Nj(’II()LLS — y'l N(‘iv Wind Fresluvafcr Amphipod. 
sleii(U‘niess boiiig (.’iiliaiK-fd by tlio yliallowiu'ss of the side plates, and 
tlie slightness of the expansion of the s(‘(‘oml joints of the hinder 
])eraeopods. Thus in females, only ])artly grown, the developing mar- 
siqtial plates liang do\vji w(dl below side-])lates 2 — 4, Avhile the oval 
braiu-liiae, both ])riinary and aeeessory, are elearly visible pendant 
betAveeii tlu' 2nd joints of the ])(‘raeo])ods.* On eacdi of x)eraeon seg- 
ments ■”) and (i two pairs of these gills occur, the more anteriorly 
phuaal a]iparently l)eing the sni)])lementary structure. 
The head is i datively short, withoid rostrum and exhibiting no 
trace ol’ eyes. 
In the pcrarDii, the segments are sub-equal, th? third, fourth and 
fifth being very slightly na.rr()wer. The dorsal margin of the side- 
j)Iates is very slightly indicated and difficult to determine. The 
fourth side-])late shows very little ])osterior euiarginatioii, and the 
lobing of side-j)lates 5 — 7 is little dev(dopeii. This slight develop- 
nruit of tlii' side ])lates, giving a sub-cylindrical shape to the slender 
hody is doubtless an ada])tation to the subterranean life, permitting 
mon‘ ready passage through the narrow crevices in the granitic rock. 
In the /deo/q tlu'. first three segments are wider than the pre- 
(•(‘diiig and as deej) as the combiiuMl depth of segment and side-plate. 
In 1h(‘ mid-dorsal line tlu'se three s('gnients each bear on the pos- 
terior margin a coiqile of a small sinqih' setae, the jieraeon segments 
and thos(‘ of the urns being devoid of such setatu 
A])peiidages, — In tlu' upper nntenuac, the three joints of the 
]>ed uncle diminisJi progressively in length and stoutness. The 
ilagcllum has twelve or tliirteim articuli (sometimes differing on 
opposite sides). The 2-joint(‘d accessory tlagidlum usually has a 
length almost equalling the first two articuli of the nmin flagellum, 
but is occasionally found nmch shorter, the second (terminal) joint, 
in these cases benig very small. In one s]H‘cimeii, on one side, there 
wei'e prt‘sont thret', almost etjual, joints. 
Of the Inirer antcuua, the two i)roximally situated joints of the 
]um1uiicU- are fused with the In-ad, tlie sutures remaining quite dis- 
tinct; the Ihrte succeeding joints (d — 5) are stout, the third much 
the shortest, tlie fourth slightly longer than the fifth. The flagel- 
him. also, is relatively stouter than tliat of the upper aiitenna, 
consists of seven joints which together are very slightly longer than 
the three free joints of the peduncle. 
The mouth ])arts have already been described in some detail 
in the specific diagnosis. A few fnrtlier notes may be added here. 
The upper Up (PI. Vlll. Fig. 2) is rounded, as in NeonipJiargus 
spenceri^ but much more setose. The lower Up (PI. VIII. Fig. 3) 
*Cf. Niphargus pulclieJIus Sayce (1900, Vol. 12, PI. 15, Fig. 1). 
