LIMNOR1A. 349 



I SOP ODA . A SELLID^E. 



NORM ALIA. 



Genus LIMNORIA. (Leach.) 



Generic character. Oblong-ovate, depressed ; antennae sub- 

 equal, cylindrical, not longer than the cephalon. Pereiopoda 

 nearly alike, slender. Pleon six-jointed. Branchial plates naked. 

 Terminal segment large, semicircular, -with a lateral appendage 

 on each side bearing two terminal slender styles. 



THE small animal which forms the type of this 

 genus is oblong, rounded in front and behind, and sub- 

 depressed. The head is short and round, with the eyes 

 wide apart, composed of but few facets. The antennse 

 are of nearly equal length, being scarcely longer than 

 the head, and terminated by a bristly pencil of hairs, the 

 upper pair composed of three small joints and a small ex- 

 articulate flagellum, and the lower pair also composed of 

 three joints, with a small articulated flagellum. The outer 

 foot-jaws consist of a long basal joint, closely united to 

 the following, the inner apical angle of which is con- 

 siderably dilated, produced and setose ; the four following 

 joints are also short, with their inner angles similarly pro- 

 duced. At the base is attached an elongated triangular 

 plate ; this plate is developed to its fullest extent in the 

 Idoteida. The mandibles are elongated, flattened, horny, 

 broadly truncated at the extremity, and furnished with 

 a triarticulate palpiform appendage. The first pair of 

 maxillae consist of two very delicate elongated plates, the 

 inner one being the more slender and curved; both are 

 setose at the tip, but the inner has, moreover, a strong 

 curved spine at its inner extremity. The second pair of 



