218 



ledge of this joint placed at a higher level than the posterior, apical claws com- 

 paratively slender. Mandibles of normal structure, with the palp rather large 

 but imperfectly jointed, vibratory plate well developed, being provided with 3 

 plumose setae and a rudiment of a 4th. Maxillae with the terminal joint of 

 the palp rather prolonged, narrow cylindrical in shape, vibratory plate with only 

 one of the setae at the base deflexed. Legs comparatively slender, rapidly 

 increasing in length posteriorly. Caudal lamellae provided behind with a knob- 

 like prominence carrying 2 divergent setae. Copulative appendages of male 

 with the terminal part somewhat imperfectly defined and more or less boot- 

 shaped. 



Remarks. This genus is chiefly characterised by the short rhomboid 

 shape of the shell, and by the want of any lateral expansions of the valves. 

 In the structural details some well marked differences are found between 

 this and the succeeding genus. It comprises several species both from the 

 northern Ocean and from more southern latitudes. 4 species, belonging to the 

 Fauna of Norway, will be described in the sequel. 





113. Loxoconcha impressa, (Baird). 



(PI. C). 

 Cy there impressa, Baird, British Entomostraca, p. 175, pi. XXI, fig. 9. 



Syn: Cy there viridis, Lilljeborg (not O. Fr. Miiller). 

 , , flavida, Zencker. 



, rhomboidea, Fisher. 



elliptica, Brady. 

 Loxoconcha rhomboidea, G. O. Sars. 



Specific Characters. Female. Shell rather tumid, seen laterally, short 

 rhomboid in shape, greatest height in the middle and about equal to 2 / 3 f 

 the length, dorsal margin boldly arched and sloping somewhat more steeply 

 in front than behind, ventral margin slightly sinuated anteriorly and evenly 

 bowed behind, anterior extremity obliquely rounded, posterior bluntly prominent 

 above and oblique below; seen dorsally, broadly fusiform in outline, with the 

 greatest width in the middle and exceeding half the length, side-edges boldly 

 curved, both extremities narrowly contracted and sharply pointed at the end. 

 Surface of valves marked with densely set small impressed pits, and moreover 

 provided with a limited number of somewhat more conspicuous knob-like 

 tubercles; inner duplicatures rather broad and crossed by distant fine pore- 

 channels, edges thin and clothed with scattered delicate hairs. Eyes very 

 conspicuous and widely apart. Anterior antennae exceedingly slender, with the 



