174 THE VOYAGE OF H.M.S. CHALLENGEE. 



4. Cytherella pulchra, G. S. Brady (PL XLIV. fig. 3, a, h). 



Cythet-ella jpulchra, Bi-ady, Trans. Zool. Soc. (18&5), vol. v. p. 361, pi. Ivii. fig. 1, a-d. 



Valves oblong, subelliptical, nearly equal in heigbt throughout, height equal to more 

 than half the length, rounded evenly in front and obliquely behind, dorsal margin 

 nearly straight, ventral straight or slightly convex ; seen from above, the outline is 

 compressed, ovate, widest somewhat behind the middle. Shell-surface smooth. Length, 

 l-32d of an inch ['77 mm.). 



Valves referable, as I think, to this species, were found in dredgings from off 

 Bermudas, 435 fathoms, mud (Station 33) ; from Port Jackson, Australia, 2 to 10 

 fathoms; from lat. 39° 32' S., long. 171° 48' E., 150 fathoms, grey ooze (Station 167) ; 

 and from off Ascension Island, 420 fathoms (Station 344). The type specimens were 

 from an Australian dredging. 



[PL XLIV. fig. 3, a, h. a Valve seen from outside, h from above.] 



5. Cytherella truncata, G. S. Brady (PL XXXVI. fig. 3, a-d). 



Cytherella tnmeata, Brady, Les Fonds de la Mer, p. 154, pi. xix. figs. 3, 4. 



Carapace, as seen from the side, oblong, subelliptical, height nearly equal throughout, 

 and correspondiug to about half the length ; extremities nearly equal, rounded, dorsal 

 margiu straight, ventral slightly concave and obscurely angular at its junction with the 

 posterior margin ; seen from above, the outline is compressed, ovate, more than twice as 

 long as broad, widest behind the middle, anterior extremity subacuminate, posterior 

 subtruncate and slightly mucronate in the middle ; end view ovate, pointed above and 

 below, widest in the middle. Surface of the shell smooth, and unsculptured. Length, 

 l-30th of an inch ('85 mm.). 



The specimens described in Les Fonds de la Mer were found at Colon-Aspinwall. 

 Those obtained during the Challenger Expedition are from Torres' Straits, 155 fathoms, 

 sand (Station 185). 



[PL XXXVI. fig. 3, a-d. a Shell seen from left side, h from above, c from below, 

 d from front. Magnified 40 diameters.] 



6. Cytherella 2nmctata, G. S. Brady (PL XXXVI. fig. 6, a, h, and PL XLIV. 

 fig. 4, a-g). 



Cytherella punctata, Brady, Trans. Zool. Soc, vol. v. (1865), p. 362, pi. Ivii. fig. 2, a, h. 



Carapace oblong, compressed ; seen from the side, reniform, of equal height before 

 and behind, extremities well and evenly rounded, dorsal margin nearly straight in the 

 middle, and gently curved towards the ends, ventral deeply sinuated ; height equal to 

 at least half the length ; seen from above, compressed, ovate, widest behind the middle. 



