533- 

 p. 1149. 



VII, p. 257, pi. LIX, 



82 



GooD descriptions of the genus are to be found in the works of Reeve, Fischer and 

 Clessin. The génotype as selected by Iredale is Isognomon isogonum ^) (Linn.). 



I. Isognomon isognomnm (Linn.). 



741. Winkelhaak Rumphius, Amboin. Rarit., p. 158, pi. XLVII, fig. i. 



753. Isognomon Nigricans ex ftisco Klein, Tentamen Méth. Ostracol., p. 121, pi. VIII, fig. 15. 



758. Coucha Volsella dicta Seba, Thés., III, p. 181, pi. XCI, figs. 6, 7. 



758. Ostrea Isognoimini Linnaeus, Syst. Nat., (éd. X), p. 69g. 



764. Ostrea Isognonion (ex parte), Linnaeus, Mus. Lud. Ulric , p. 



767. Ostrea Isogonum (ex parte), Linnaeus, Syst. Nat., (éd. XII), 



767. Isognomon Petiver, Anim. Amboin., p. 4, pi. XX, fig. 11. 



780. Huitre Favanne, Conch., pi. XLIII, figs. Bi, Bi. 



784. Norma Gnomon sp. Isognomoni perfecti Chemnitz, Conch. -Cab., 



fig. 584. 

 788. Melina Isogonum Retzius, Nov. Test. Gen., p. 23. 

 788. Ostrea Isogonum Barbut, Gen. Verm., p. 56, pi. IX, fig. 4. 

 791. Ostrea Isognomnm Gmelin, Syst. Nat., (éd. XIII), p. 3338. 

 791. Bruguière, Encyclopéd. Méthod., pi. CLXXVI, fig. l. 



798. Isogonnni Gnomon (ex parte), Roding, Mus. Boltenianum, p. 168. 

 802. Perna isogona Bosc, Hist. Nat. Coq., II, p. 283, pi. XII, fig. 3. 

 817. Pedalion Isognomon Dillwyn, Descr. Cat., I., p. 822. 

 819. Perna Isognomum Laniarck, Anim. sans Vertèb., VI, p. 140. 

 819. Perna femoralis var. b., Lamarck, op. cit., p. 140. 



824. Perna Isogonum Blainville, Dict. Sci. Nat., XXXII, p. 314, pi. XC, fig. i. 

 830. Perna fémorale var. B, Blainville, Man. Malacol., pi. LXIII, fig. i. 

 850. Perna isognomiwi Deshayes in Cuvier, Règne Anim., pi. LXXXI, figs. i, \a. 

 855. Ostrea Isognomum Hanley, Ipsa Linn. Conch., p. 118. 

 855. Perna Isognomon Berge, Conchylienbuch, p. 88, pi. XXII, fig. 4. 

 862. Perna isognomon Bronn, Thierreich, Klass. Ord. Weichth., III, Atlas I, pi. XLI, fig. 10. 



886. Perna [Isognomon) isogonum Fischer, P., Man. Conchyliol., p. 956. 



887. Perna isognomon von Martens, Journ. Linn. Soc. London, (Zool.), XXI, p. 203. 

 890 — 91. Perna isogonum Clessin in Martini-Chemn. Conch. -Cab. (N. F.), VIII (I), Malleacea^ 



pp. 27, 41, pi. VIII, fig. I, pi. XV, fig. 2, pi. XV c, fig. I. 

 898. } Perna isognomon Melvill & Standen, Journ. Conch., IX, p. 81. 



909. Perna isognomon Lynge, D. Kgl. Dansk. Vidensk. Selsk. Skr. Nat. -Math., (7) V, p. 147. 

 909. Melina isognomum Lamy, Bull. Mus. d'Hist. Nat., Paris, XV, p. 468. 

 911. Isognomum [Perna] isogîiomum Feheneer, "Siboga" Lamellibranches (Anat.), p. 26, pi. VII, 



figs. 6, 7. 

 919. Perna isognomon Odhner, Arkiv Zool., XII, N" 6, p. 5. 

 925. Pedalion [Isogonum) isognomum Oostingh, Geol. Comm. Agr. Univ. Wageningen, N" 9, 



p. 244. 



928. Pedalion isognomum B'austino, Summary Philippine Mar. Freshw. Mollusks, p. 25. 



929. Isognomon isogonum Dautzenberg, Faun. Colon. Français., III, p. 566. 



As a resuit of careless citations of the figures of the earlier authors a great deal of 

 confusion was introduced in référence to the form named Ostrea isognomiim by Linnaeus. In 

 "Systema Naturae" (éd. X), he cited Rumphius pi. XLVII, fig. i and Klein pi. VIII, fig. 15 

 for figures of his species. Both thèse figures represent a form with a relatively narrow, elongate 

 and somewhat arched shell and provided with a comparatively long and narrow auricle. In 



i) Iredale wrongly spells the spécifie came as isogiicmon but the correct Linnean spelling is isognomum. 



