10 ^ 
Nicholls — Neiv Geiras and Species of Amphipods. 
U. affinis, sp. iiov. (PI. Xlll. I'^igs. 10-15). 
Specific Diagnosis . — All tlir pU'on sogineiits cxee])t the last 
vitli at least a pair of dorsal or dorso-lateral setules; fourth and 
iftli segments ■with two aJid three i>airs respectively. 
Somcnvliat degenerate eyes distinctly to be made out in life, 
lot readily to be observed in specimens pi’eserved in s])irits. An- 
eiina 1 about half the length of l)ody, accessory flagellum 4-0 
joints. Antenna 2 not so stout as in U. wcstralis, 10 jointed 
lagellum relatively sliorter ;ni<l more slender -with an olfactory 
•ylinder on the penultimate joint. 
Gnatliopod 2 larger than giiatho[)od 1. Ppon the inner aspect 
)f the basos of this limb is a seines of four traiisvci'se ridges 
'ach bearing from three to five stout sjiines. Distal lobe upon 
.•arpus Avell developed, projuxl oval, obli(jU(‘ separated only 
from convex posterior border of the joint by a triangular pro- 
jection bearing two stout spines iietween 'which the tip of the 
lactyl is received; accessory gills considerably branched are found 
on some of the app(mdages of the jieraeon. Uropod 2 with basal 
joint nearly as long as broad; inner ramus small, outer two 
jointed; comb-like ])late on proximal joint, bearing from 18-21 
stiff, closely-set setae; terminal joint as long as inner ramus and 
less than one fourth the length of entire ajjpendage. Telson, cleft 
almost to the base, three-fourths as long as broad and ecjual to 
length of proximal joint of third uroinnl ; a small basal portion 
curved into a shallow hood-like ])iece continuing the dorsal surface 
of pleon from Avhich the cleft portion projects at a sharp angle. 
Length . — Not exceeding 9 mm. 
Colour . — In life yellow In-own, somewhat translucent, chalk- 
white eyes sometimes appearing faintly pink tinted; in 
females the ovary is discernable through the body wall 
and gives a faintly pink tint which is much more notice- 
able when the brood pouch is filled with large eggs of 
salmon pink colour. 
Habitat . — hound abundantly near the origins of many small 
S 2 )rings around Darlington and Mundaring; usually hitling 
under deca>ying vegetable matter or actually burrowing 
in the sandy or gravelly soil beneath the flowing water. 
Ixcmarks. — affinis may be distinguished from U. ivcstralis, 
which it is closely related, by its distinctive colour, and the 
ijreseJice of degenerate eyes. It a 2 )pears to differ from that S 2 )ocies 
also in the slightly more slender second antenna (Ph Xlll, Pig. 
13-14), and telson (PI. XIII, Pig. 15). 
