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 'paludris 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. (^ 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 antennae are very small, though comparatively moderately stout ; 

 the secondary branch is small and one-jointed and provided with a few 

 apical seta? (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 setae (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 Erihydrosoma 

 curvatum, Brady and Eobertson, 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 setae 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 setae 

 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 setae 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 



