274 STUDIES ON AUSTRALIAN MOLLUSCA, xi., 



seem to have appeared in American literature. Amphidesma 

 zebuense Hanley, seems to be to me indistinguishable from S. 

 duplicates. 



Semele exarata Adams & Reeve. 

 (Plate xvii., figs. 34, 35, 36, 37.) 



Amphidesma exarata Adams and Reeve, Voy. Samarang, Moll., 

 1850, p. 81, PI. 24, fig. 9. 



Figures are here presented of a specimen in the British Museum, 

 dredged in 7 fathoms, fine sand, near Singapore, by H. Cuming. 

 It is 28 mm. long, 22-5 high, and 6 mm. in depth of single valve. 



Psammobia squamosa Lamarck. 



Psammobia squamosa Lamarck, Anim. s. vert., v., 1818, p. 514; 

 P. rugulosa Adams and Reeve, Voy. Samarang, Moll., 1850, p. 81, 

 PL 24, fig. 4; P. palmula Deshayes, Proc. Zool. Soc, 1854 (1855), 

 p. 325. 



Study of the series in the British Museum induces me to regard 

 P. rugulosa as a synonym of P. squamosa, and with these to unite 

 P. palmula, the latter only differing from the rest by being white 

 and smaller. One specimen, apparently the type of P. palmula, is 

 marked "Sydney." But this is an error, for the species does not 

 ascend to so high a latitude. 



Donax striatellus Deshayes. 

 (Plate xvii., figs. 38, 39.) 

 Donax striatellus Deshayes, Proc. Zool. Soc, 1854,(1855), p. 352. 

 This unfigureel species was reported from "Australia." No fur- 

 ther information about it has been contributed by subsequent 

 writers. The present illustration is taken from a specimen, which 

 is apparently the type of Deshayes, but not so marked, in the 

 British Museum, which measures, height, 17 ; length, 30 ; and depth 

 of conjoined valves, 10-5 mm. 



Donax veruinus, nom.mut. 

 Donax nitida Reeve, Conch. Icon., viii., 1854, PI. vi., fig. 34; Id., 

 Deshayes, Proc. Zool. Soc, 1854,(1855), p. 350; Id., Smith, Chall. 

 Rep. Zool., xiii., 1885, p. 112 ; Id., Melvill and Standen, Proc Zool. 



