462 Part III. — Tvjentieth Annual Report 



of six joints. The secondary branches of the antennae (posterior antennse) 

 are small and two-jointed. Mandibles stout, mandible-palp well 

 developed and provided with two branches, Other mouth organs similar 

 to those in Mesoclira and Oletodes. The first four pairs of thoracic feet 

 have the outer branches three- and the inner branches all two-jointed. 

 Fifth somewhat rudimentary and composed of a single lamelliform joint. 

 Ovisacs apparently double. 



Psetulomesochra differs from Mesoclira, Oletodes, and allied genera 

 chiefly in the structure of the mandible-palp and fifth pair of feet. 



Pseudomesochra longifurcata, T. Scott (sp. nov.) PI. XXIV., figs. 27-35. 



Description of the Female. — Length about •5mm. (J^ of an inch). 

 Body moderately stout, tapering slightly towards the posterior end ; 

 abdomen not distinct from thorax ; rostrum small ; caudal furca elongated, 

 being nearly equal to the entire length of the last three abdominal 

 segments (fig. 27). 



Antennules short, moderately stout, and composed of six joints, the 

 first two and the last being each considerably longer than any of the 

 other three (fig. 28). The approximate proportional lengths of the 

 various joints are shown by the formula : — 



Proportional lengths of the joints, - 23 • 20 • 8 • 5 • 4 • 15 



Numbers of the joints, - - - 1'2"3'4'5*6 



The antennae are of moderate size ; secondary branches two-jointed and 

 provided with several marginal and terminal setae (fig. 2^. ^ 



Mandibles robust and having the biting end armed with several stout 

 teeth ; mandible-palp well developed and the basal part furnished with 

 two branches (fig. 30). 



Second maxillipeds short and moderately stout, but the terminal 

 claw is rather feeble, and fringed with a few minute hairs (fig. 31). 



The first four pairs of thoracic feet slender. In the first pair both 

 branches are about the same length ; the joints of the inner branches are 

 sub-equal, and a single seta springs from the inner margin and three from 

 the end of the second joint, the proximal joint appears to be unprovided 

 with setae or spines (fig. 32). In the second, third, and fourth pairs the 

 inner branches in each are rather shorter than the outer branches, and 

 the end joints somewhat longer than the proximal ones, and in these 

 three pairs of feet the inner branches are more setiferous than the inner 

 branches of the first pair (fig. 33). The fifth pair, which are small and 

 somewhat rudimentary, appear to be composed of a single lamelliform 

 joint, bearing three long apical setse (fig. 34). 



Uahitat. — Upper Loch Etive, where it was dredged by the " Garland " 

 in over 60 fathoms on September 17th, 1901. It appears to be a rare 

 species, as only a single specimen (a female) was observed, but as the 

 species is a very small one it may be easily overlooked. 



Leptopmitia, T. Scott (gen. nov.). 



Body slender and cylindrical. Antennules (anterior antennae) seven- 

 jointed, slender. The secondary branches of the antennae are entirely 

 wanting or reduced to a single seta. Mandibles slender and moderately 

 elongate ; mandible-palp also slender and one-branched. Other mouth 

 organs somewhat as in Mesochra, Boeck. The first four pairs of thoracic 

 feet slender, outer branches three- and inner branches all two-jointed. 

 The inner branches of the first pair elongated— the end joint being the 

 shortest, the outer branches short, the inner branches of the other three 

 pairs very short, and the outer elongated. Fifth pair small, foliaceous, 

 two-branched ; secondary branches (or joints) minute. 



