LIMNICYTHERE. 



173 



Genus 2. — Limnicythere, Bradij. 



Shell irregularly tuberculated or spinous, rather thin and horny in texture. Animal 

 like that of Cythere, except that the antennae are armed with short setge, instead of spines. 

 Upper antennae five-jointed, slender, the last joint much elongated, the antepenultimate 

 excessively short. Post-abdomen terminating in two rather stout setae. 



Freshwater habitat. 



1. Limnicythere inopinata {Baird). Plate X, figs. 8 — 11. 



1850. Cythere inopinata, Baird. Brit. Entom., p. 1/2, pi. xx, figs. 1, 1 a—e. 

 1868. Limnicythere — Brady. Monog. Kec. Brit. Ostrac, p. 419, pi. xxix, 



figs. 15 — 18; pi. xxxviii, fig. 9; pi. xxxix, 



fig. 1. 



Carapace, as seen from the side, reniform, greatest height near the middle and some- 

 what exceeding half the length ; anterior extremity evenly, posterior obliquely rounded, 

 and fringed below the middle with a series of from six to twelve small sharp teeth ; 

 superior margin forming a flattened arch, inferior deeply sinuated in the middle. Seen 

 from above, the outline is irregularly ovate, conspicuously and sharply mucronate in front 

 and more obscurely behind ; greatest width behind the middle, and scarcely equal to half 

 the length. Surface of the valves finely punctate, once or twice transversely sulcate, and 

 usually bearing from one to three tubercles ; margins produced into a compressed en- 

 circling flange. Colour yellowish. 



Length, -^th of an inch. 



The tuberculation and general surface-sculpture of this species vary very much; 

 sometimes, as in the specimen here figured, there is scarcely any tuberculation ; in other 

 cases there may be one, two, or three tubercles, which of course very much modify the 

 -outline of the shell when viewed from above. Our fossil specimens, however, are as a 

 general rule less uneven than the recent ones. 



Distribution. Recent. — Great Britain, Ireland. 



Fossil. — Scotland : Crofthead, Dipple. England : Hornsea, Branston Fen. 



