v 
of the Fishery Board for Scotland. 467 
similar situations in various parts of the British Islands as well as on the 
Continent, was during the preceding summer (1901) obtained near 
Newburgh on the Ythan, Aberdeenshire. Both the males and females 
of Nannopus palustris were obtained in the brackish water pools at this 
Aberdeenshire Station, and as no description or drawing of the male has 
yet, so far as I know, been published, the following notes on both of the 
sexes may be of interest. 
The body of the female seen from the dorsal aspect is moderately stout 
anteriorly, but tapers gradually and evenly towards the posterior end 
(fig, 13); the female specimen represented by the drawing measures 
about *9 mm. (54 of an inch) in length. 
The antennules, which are short and stout, are composed of five joints, 
the penultimate joint being very small; the last four joints are 
densely setiferous, but the sensory filament (asthetask) which springs 
from the end of the third joint is comparatively short and slender 
(fig. 15). 
The antennz are very small, though comparatively moderately stout ; 
the secondary branch is small and one-jointed and provided with a few 
apical sete (fig. 16). 
The mandibles are moderately stout, their biting end is somewhat 
truncate and provided with a few stout teeth ; the mandible-palp consists 
of a one-jointed and somewhat dilated appendage articulated near the 
base of the mandible and provided with a few short sete (fig. 17). 
The second maxillipeds are small, the terminal claws are moderately 
stout and carry a few minute hairs on their inner margins (fig. 18). 
In the first four pairs of thoracic feet the outer branches, which are 
moderately stout, are all three-jointed and armed with elongate 
though somewhat slender spines on their outer margins; the inner branches 
of the first, second, and third pairs are considerably shorter than the 
outer, and each composed of two joints, but the inner branches of the 
first pair are rather smaller than those of the second and third (fig. 19). 
The inner branches of the fourth pair are rudimentary and consist of 
a single minute joint which carries a very small and a moderately 
elongated seta (fig. 20). 
The fifth pair resemble somewhat closely the fifth pair in Hnhydrosoma 
curvatum, Brady and Robertson, the basal joint is very broad and short, 
they form short lamelliform plates along the postero-ventral margin of 
the last thoracic segment, four moderately stout plumose setz spring from 
the edge of the inner half of each basal joint; the secondary joints are 
small and sub-rotund, and each furnished with five moderately long sete 
round the distal margin (fig. 21). 
The caudal furca are very short. 
Description of the Male.—The male differs little from the female except 
in the following points; it is, when seen from above, distinctly narrower 
than the female, especially towards the anterior end (fig. 14), The anten- 
nules are shorter and less prominent, the basal joints are also more 
dilated, but the antennules taper quickly towards the distal end, the pen- 
ultimate joint is considerably swollen and assumes a utricule-like form, 
while the end joint is very small (fig. 23). 
The mouth organs in the male appear to be very similar to those of the 
female. The thoracic feet are also similar in both sexes, except that the 
inner branches of the third pair are provided with a short but stout ter- 
minal spine slightly hooked at the end, and a single plumose seta instead 
of a moderately long slender spine and two plumose sete as in the third 
pair in the female (fig. 24). The fifth pair in the male resemble those of 
the female, except that the secondary joint appears to be almost obsolete 
