1901.] MOTHER-Or-PBAEL OYSTERS. 3S7 



Avicula nebulosa, Conrad, Reeve, 1857, sp. 33, figs. 33, 34 ; 

 Sandwich Islands. Type B.M. 



Avicula (Meleagrina) licMensteinii, Dunker, 1852, p. 77 ; 1872, 

 p. 10, tab. 2. fig. 3 ; Sandwich Islands. 



=31. vulgaris (Schumacher), fide Cooke, 1886. 



If this shell is specifically distinct, which can only be proved by 

 comparison of a larger series than that available in the British 

 Museum, it is very closely allied to 21. vulgaris. I fully expect 

 that it will tui-n out to be merely a local form of Schumacher's 

 species. Some of the specimens in the British Museum show a 

 tendency to the predominance of orange ground-colour with black 

 markings. Such a coloration is not unknown in examples of 

 31. vulgaris. The largest examples in the Museum, about the size 

 of five-year old Ceylon shells, are practically indistinguishable 

 from specimens from the Gulf of Manaar. 



Distribution. Oman, Sandwich Islands (B.M., collect. Nuttall) ; 

 Sandwich Islands (Mus. Cuming). 



The " Nuttall " specimens are probably the types or cotypes of 

 Conrad's two species. 



Species 16. Makgaritifeea timbriata. 



Avicula finibriata., Dunker, 1852, p. 79 ; "Central America." 

 Avicula {Meleagrina) fimhriata, Dunker, 1872, p. 13, tab. 3. 

 figs. 2 & 6. 



This shell has been confused by Carpenter (1857) with 31. 

 margariiifera var. mazatlanica, on the strength of Dunker's 

 description in 1850. Dunker's figures (1872) represent a species 

 that is certainly not M. margaritifera, but probably a Central 

 American representative of the Lingah shells. Dunker does not 

 inform us whether it occurs on the Atlantic or Pacific side of the 

 Continent. 



Species 17. Margaritifera leis^tiginosa. 



Avicula lentiginosa, Eeeve, 1857, sp. 13 ; Moluccas. Type in B.M. 

 ( = M. vulgaris, fide Cooke, 1886.) 



The "White Banda" shell of the trade. 



At present, unfortunately, the White Banda shell is not to be 

 procured in the London markets. The couple of specimens that 

 I have seen in City warehouses closely resemble Heeve's type of 

 this species. They differ mainly from 3£. vulgaris in being larger, 

 somewhat flatter, and of a greyish external colour. The White 

 Banda shell is said to be fished in deep water, associated with the 

 Macassar shell (31. nuuvima). 



Species 18. Margaritifera pr^testa. 



Avicula prcBtexta, Eeeve, 1857, sp. 15 ; Island of Corregidor, 

 Philippines. Type in B.M. 

 (? = iW. lentiginosa.) 



