283 



1903- Papyridea rugata Hidalgo, Obras Malacol., II, p. 343. 



1905. Papyridea rugata Hidalgo, Cat. Filip., p. 346. 



1906. Cardium apertuin Owston, Japan. Loochooan Shells, p. 39. 



1909. Cardium [Papyridea) rugatiim Lynge, D. Kgl. Dansk. Vidensk. Selsk. Skr. Nat.-Math., 



(7) V, p. 258. 

 191 1. Papyridea rugata Pelseneer, "Siboga" Lamellibranches (Anat.), p. 57, pi. XXI, fig. 5. 



C. (P.) apertum is the type of the section Fulvia Gray ^), which is distingulshed from 

 Papyridea s. s., by the margin of the gape being entire and not serrated. 



The species varies greatly in référence to its sculpture. The radial thread-like ridges may 

 be quite prominent and the middle of the shell below the umbones decussated. In other shells, 

 however, there are only a few distinct ridges on the anterior and posterior régions of the valves, 

 while the rest of it appears almost smooth. The colour of the shells is also variable. 



Distribution : — C. [P.) aperhim has been recorded from Japan to Java in the Pacific 

 Océan and as far west as the Mergui Archipelago in the Indian Océan. 



In the "Siboga" collection it is represented by shells collected in the Bay of Pidjot, 

 Lombok (St. 33), Bay of Bima (St. 47), Sulu Harbour, Sulu Island (St. 104), Anchorage off 

 Lirung, Salibabu Island (St. 133), Banda Anchorage (St. 240), Buka or Cyrus Bay, south coast 

 of Rotti Island (St. 299). 



Genus Corculum Roding. 



1798. Corcuhim Roding, Mus. Boltenianum, p. 188. 



1799. Hemicardia Spengler, Skr. Nat. Selsk., V, pp, 48, 53. 



181 1. Cardissa Megerle, Mag. Ges. Naturf. Freunde Berlin, V, p. 52. 



1822. Hemicardium Férrusac, Tabl. Syst., p. XLIII. 



1857. Hemicardia Adams, H. & A., Gen. Rec. MolL, II, p. 458. 



1887. Hemicardia Fischer, P., Man. ConchylioL, p. 1058. 



1900. Corculum Dali, Trans. Wagner Free Inst. Sci. Phlladelphia, III, p. 1077. 



1930. Corculum and Hemicardium Stewart, Spécial Publication Acad. Nat. Sci. Philadelphia, 

 pp. 269, 270. 



The différences betvveen Corcuhim Roding and Hemicardium Spengler, as the two gênera 

 are restricted by Stewart, are not of any importance and I hâve, therefore, united the two 

 under the older Corcuhtm^. The génotype of Corcttlum is CorcMlum cardissa (Linn.) designated 

 by VON Martens in rSyo. 



I. CorcMlum cardissa (Linn.). (Plate VI, figs. 33, 34). 



1685. Pectuucidus maculatus etc. Lister, Hist. Conch., pi. CCCXVIII, fig. 155. 



1741. Chaîna Cardissa Rumph., Amboin. Rarit., p. 132, pi. XLIII, fig. E. 



1742. Concha Cordiformis etc. Gualtieri, Ind. Test., pi. LXXXIV, figs. B, B, C, D. 

 1753. Hemicardia convexo convexa etc., Klein, Tent. Meth. Ostr., p. 137. 



1757. Cor hominis seu Veneris D'Argenville, La Conch., pp. 294, 299, pi. XXIII, fig. i, pi. LI, 



fig. E2. 



1758. Cardium Cardissa Linnaeus, Syst. Nat., (éd. X), p. 678. 



1764. Moule en Coeur Knorr, Délices Yeux, I, p. 34, pi. XVIII, figs. 3, 4. 

 1764. Cardium Cardissa Linnaeus, Mus. Lud. Ulr., p. 484. 



i) Gray, J. E. — Ann. Mag. Nat. Hist., (2) XI, p. 40 (1853) see also Dall, W. H. — Trans. Wagner Free Inst. Sci. Phila- 

 delphia, III, p. 1076 (1900). > 



