64 THE VOYAGE OF H.M.S. CHALLENGER. 



ovate, widest below the middle; the shell of the male (fig. 3, e,f) is narrower, and, seen 

 laterally, is more tapered towards the hinder end. Shell-surface quite smooth. Length, 

 l-55th of an inch ("46 mm.). 



The only specimens of this species brought home by the Challenger were found in 

 anchor-mud from Vigo Bay ; they are ill-grown, and do not exhibit the delicate, punctured, 

 and papillose ornament which is usually found in British specimens ; the headquarters of 

 the species appears to be the North Sea, though I have examples also from the Mediter- 

 ranean and the Bay of Biscay. It occurs, too, though very sparingly, as a Post-Tertiary 

 fossil in Wales, Scotland, and Norway. 



[PI. XII. fig. 3, a-f. a Carapace of female seen from left side, h from above, c 

 from below, d from front, e male seen from left side, f from below. All magnified 

 60 diameters.] 



4. Cythere velUcata, n. sp. (PI. XII. fig. 2, a-d). 



Carapace elongated, compressed, seen from the side, subreniform, height scarcely 

 equal to half the length, and nearly the same before and behind ; anterior extremity 

 well rounded, posterior obliquely truncated, and looking upwards ; dorsal margin very 

 slightly arched, highest in the middle, and sloping almost imperceptibly to each extremity, 

 ventral deeply sinuated in the middle, and inclined rather abruptly upwards behind ; 

 seen from above, the outline is nearly cuneifoi'm, very narrow, widest at the posterior 

 extremity, the width being equal to one-third of the length ; sides nearly parallel for 

 the greater part of their course, but converging in front of the middle, and ending in 

 an obtuse anterior extremity ; at the hinder end the lateral margins terminate abruptly 

 in a right angle, the extremity being truncated, and having a large central mucronate 

 process ; end view subovate, widest in the middle. Surface of the shell smooth, and 

 somewhat undulated. Length, l-58th of an inch ("44 mm.). 



A small but very distinctly characterised species not unlike Cythere castanea in 

 lateral outline, but abimdantly separated from it by the wedge-shaped dorsal outline, and 

 the want of punctured surface ornament. 



Dredged at Port Jackson, Australia, in a depth of 2 to 10 fathoms. 



[PL XII. fig. 2, a-d. a Shell seen from left side, b from above, c from below, d from 

 front. Magnified 80 diameters.] 



5. Cythere moseleyi, n. sp. (PI. XII. fig. 5, a-f). 



Carapace of the female, as seen from the side, oblong, subquadrangular, somewhat 

 higher in front than behind, height equal to half the length ; anterior extremity well 

 rounded, posterior narrower, and obliquely truncated, with very slightly rounded angles ; 

 dorsal margin slightly arched, and sloping gently from before backwards, ventral slightly 

 sinuated in front, and trending upwards behind the middle ; seen dorsaUy, the outline is 



