1858. Pinna Hanleyi, P. /iirida, P. serra, P. Japonica, P. Chemnitzii and P. assiinilis Reeve, 

 Conch. Icon., XI, Pinna, pi. VIII, fig. 15; pi. XIII, fig. 24; pi. XXIII, fig. 43; pi. XXV, 

 fig. 47; pi. XXIX, fig. 55; pi. XXXI, fig. 59- 



1858. Pinna Chemnitzii Hanley, Proc. Zool. Soc. London, p. 136. 



1859. Pinna Chevinitzii Reeve, Conch. Icon., XI, Pinna, pi. I, fig. i. 



1860. Pinna assimilis, P. Chemnitzii, P. Hanleyi, P. Japonica, P. lurida and P. serra Reeve, 



Elem. Conch., II, p. 69. 



1866. Pinna pectinata, P. Hanleyi, P. Japonica, P. serra, P. Chemnitzii and P. assimilis von 



Martens, Ann. Mag, Nat. Hist., (3) XVII, pp. 85, 86. 



1867. Pinna Chemnitzii Hidalgo, Journ. ConchylioL, XV, p. 170. 

 1869. Pinna Japonica Lischke, Jap. Meeres-Conch., p. 159. 

 1882. Pinna Chemnitzii Dunker, Ind. Moll. Mar. Japon., p. 231. 



1889. Pinna Chemnitzii Morlet, Journ. ConchylioL, XXIX, p. 161. 



1890. Pinna serra and P. Japonica Clessin, in Martini-Chemn. Conch. -Cab. (N. F.), VIII (I), 



Malleacea, p. 60, pi. XXVIII, fig. i. 



1890. Pinna assimilis, P. Chemnitzii, P. Hanleyi, P. Japonica, P. lurida and P. serra Paetel, 



Cat. Conch. Samm., III, pp. 208, 209. 



1891. Pinna Lischkeana, P. Hanleyi, P. lurida, P. Chemnitzii and P. assimilis C\&?,sin,ïn ^idiVthii- 



Chemn. Conch.-Cab. (N. F.), VIII (I), Malleacea, p. 72» pl- XXVIII, fig. i; p. 89, 

 pi. XXXVIII, fig. 2; p. 93, pi. XLI, fig. I and p. 97, pi. XLVI, fig. i. 



1891. Pinna serra Smith, Proc. Zool. Soc. London, p. 433. 



1906. Pinna chemnitzii Standen & Leicester, Ceylon Pearl Oyster Rept. V, p. 290. 



1909. Pinna serra Lynge, D. Kgl. Dansk. Vidensk. Selsk. Skr. Nat. -Math., (7) V, p. 149. 



191 7. Pinna Chemnitzi Odhner, Kungl. Sv. Akad. Handling., LU, N" 16, p. 7. 



1924. Pinna Chemnitzii Hedley, Rec. Austral. Mus., XIV, p. 149. 



1929. Pinna {Atrina) pectinata Winckworth, Proc. Malacol. Soc. London, XVIII. p. 288. 



I hâve examined the entire material in the British Muséum (Nat. Hist.), London and 

 several other collections, and agrée with Winckworth that there exist ail gradations between 

 the strongly spinous form described as P. assimilis by Reeve and the almost smooth form which 

 was cjiven the name P . lurida. Further, the wrinkling^ of the ventral surface of the shell is 

 also very variable and intermediates connect up the forms described as P . hanleyi and P . lurida. 

 The outline of the dorsal margin may be straight or incurved. 



Distribution : — P. {A.) pectinata is widely distributed in the Indo-Pacific area. For 

 détail of localities référence may be made to Winckworth's paper cited above. 



In the "Siboga" collection there are two somew^hat broken young shells resembling the 

 form figured as P. serra in "Conchologia Iconica" from St. 294 (10° 12^.2 S., 124° 2'j\t, E. :, 

 depth 173 mètres). 



Subgenus Streptopinna von Martens. 



1880. Streptopinna von Martens, Môbius Beitràge Meeresf. Mauritius, Seychell., p. 318. 

 1929. Streptopinna Winckworth, Proc. Malacol. Soc. London, XVIII, pp. 282, 283. 



This peculiar subgenus has been recently discussed in détail by Winckworth. The type 

 of the monotypic subgenus is Pinna {Streptopinna) saccata Linn. 



I. Pinna {Streptopinna) saccata Linn. 



1741. Pinna prima sive oblonga and P. alba Rumph, Amboin. Rarit., p. 153, pi. XLVI, figs. I, k, n. 

 1758. Pinna saccata Linnaeus, Syst. Nat., (éd. X), p. 707. 



