144 PROCEKDINfiS OF THE M ALACOI.OGICAL SOCIETY. 



23. Mac'tea meea, Deshayes. B.M. 



Mactra mera, Deshayes, Proc. Zool. Soc, 1853, p. 16; Heeve, fig. 82 ; 



Weinkautf, pi. xxxvi, fig. 7. 

 M. antiqnata, Heeve (?io« Speugler), Conch. Icon., sp. 22; Weinkauff, 



p. 41, pi. xiii, figs. 4, 5. 



Uab.—'^ydnQy (J. McGillivray in Brit. Mus.), Bay of Manila 

 (Reeve), Philippine Islands, several localities (Hidalgo), Singapore 

 and Australia (Weinkauff), Singapore and North Borneo (Brit. Mus.), 

 Chinese Sea (Deshayes for mera). 



This species is not, I think, the M. antiqnata of Spengler founded 

 on a description and figure in Chemnitz (Conch. Cab., vol. xi, p. 217, 

 pi. cc, fig. 1954), Tlie shell then described was 4 inclies in length 

 and white, both iviihin and wiihoxd^ and purplisli at the umbones. 



The species now under consideration is more trigonal, and does not 

 appear to attain such a large size, the largest specimen I have seen 

 being only 3^ inches long. It is invariably of a rich purplish-brown 

 within, and marked externally with brown radiating lines or stripes. 



The M. antiqnata of S[)engler is probably the same as M. cornea, 

 Deshayes,^ of which M. spectahilis of Lischke" from Japan is a 

 synonym. 



M. cornea was described as coming from the "Chinese Sea", one 

 of the localities given by Chemnitz in the original description. The 

 type is only a lialf-grown shell, but the species attains a very large 

 size, a specimen from Japan in the Museum collection being nearly 

 5 inches long. It is uniformly whitish externally beneath the 

 thin periostracum, excepting the purple or violet umbones. The 

 interior also is whitish excepting the upper part, which is a kind of 

 pale flesh tint. 



The type of M. 7nera is very faintly rayed, but this feature is 

 not noticed either by Deshayes or Reeve. This, however, is not 

 surprising, since the rays are only just traceable when the shell is 

 carefully examined, and might otherwise be easily overlooked. 



24. Mactra olorina, Philippi. B.M. 



Mactra olorina, Philippi, Abbild., vol. ii, p. 72, pi. ii, fig. 2, 1846; 



Reeve, fig. 35 ; Weinkauff, p. 39, pi. xii, figs. 4-6. 

 M. semisidcata, Deshayes MSS. ; Reeve, fig. 48 ; Weinkauff, p. 59, 



pi. XX, figs. 4, Aa. 



Hah. — Red Sea (Philippi, Reeve, Weinkauff for olorina), Australia 

 (Reeve and Weinkauff for semisnlcata), Persian Gulf (Fischer, J. de 

 Conch., 1891, p. 229). 



Allied to decora, but larger, differently coloured within and 

 without, and with rather finer sulcation on the anterior portion. 



Only known as Australian on Reeve's authority. 



] Proc. Zool. Soc, 1853, p. 16 ; Reeve, fig. 75. 



'^ Japan. Meeres-Conch., Theil ii, p. 120, pi. xi, tigs. 1, 2 ; Weinkauff, pi. xv, 

 figs. 1, 2. 



