FRESHWATER SHELLS OP AUSTRALIA.. 303 



127. CoKBiciJLA BARONiALis, Prime. 



Corbicula baronialis, Prime, Ann. Lyceum Nat. Hist. New York, 1870 

 vol. ix. p. 300; Clessin, Conch.-Cab. ed. 2, p. 200. 



Hah. Port Morton, Australia. 



This species is described as ovately transverse, somewhat com- 

 pressed, subequilateral, with the anterior end rounded, the poste- 

 rior subtruncate. The umbones are short, the epidermis yel- 

 lowish, the sulci irregular, more or less obsolete, the valves thin 

 and white witliin. The length is 17 millim., width 14, diam. 9. 



128. Corbicula debilis, Gould. 



Cyrena debilis, Gould, Proc. Bast. Sac. Nat. Hist. 1850, p. 293; id. 



U.S. Explor. Exped. vol. xii. p. 427, Atlas, fig. 529 a-b ; id. Otia 



Conch, p. 86; Tenison- PVoods, Proc. Linn. Soc. N. S. Wales, 1878, 



vol. ii. p. 255. 

 Corbicula debilis, Gould, Deshayes, Cat. Conch. Brit. Mus. p. 234; 



Gould, Otia, p. 246; Prime, Cat. Corbie, Am. J. Conch, vol. v. 



p. 131. 

 Hah. New Holland? {Gould, '■Otia'') ; Hunter Eiver, New 

 Holland {Prime). 



This species is remarkable on account of the depressed umbones 

 and its cycladiform appearance, 



129. Corbicula Deshatesii. (Plate VIL figs. 28-29.) 

 Shell transverse, subtriangularly ovate, inequilateral, rather 



prominent at the umbones ; anterior end shorter, rounded at the 

 margin ; posterior a little broader than in front, frequently exhi- 

 biting a slightly acute curve at its junction with the basal curved 

 margin. Epidermis more or less zoned with olive, bluish olive 

 and darker hands, with the outer edge of an orange colour. 

 TJmbones eroded, when wetted exhibiting a dark purple or violet 

 ray. Concentric sculpture coarse on the anterior part of the 

 valves, becoming obsolete from the middle posteriorly. Interior 

 wbitish in the umbonal region with a violet spot, pale violet at 

 the lower margin, witb a spot on the posterior edge beneath the 

 lateral teeth, all of which and the cardinals are almost white; 

 rest of interior dark violet zoned with a paler tint. Besides 

 the central subtrigonal ray, many specimens exhibit two others, 

 one on each side beneath the side teetli radiating from the apex. 



Variety. Shell covered with a yellowish epidermis, zoned with 

 light reddish bands. Interior pinkish at the margin and umbo, 

 bluish white with darker zones elsewhere. 



Llirar. JOURK. — ZOOLOGT, YOL. XVI. 21 



