146 PROCKEDINGS OF THK MALACOLORICAL SOCIETY. 



appropriated by Gmelin as illustrating his M. pcllucida (Syst. 

 Nat., vol. vi, p. 3260). Chemnitz gave the locality as coast of 

 Guinea. 



A single specimen from Port Curtis, Queensland, which I named 

 Mactr inula angtiUfera, Beshayes, in the Alert Report, I now 

 regard as belonging to the present species, since it lacks the sculptured 

 umbones of angulifera, " tenue et regulariter plicatis " (Deshayes, 

 Proc. Zool. Soc, 1854, p. 70). 



The umbones in M. ovalina are smooth, excepting the delicate 

 growth-lines. There are other differences between these species 

 besides the character of the umbones. In angulifera the posterior 

 oblique carina is more pronounced, and forms a distinct terminal 

 angle, and the general form is more trianguhxr. 



27. Mactr.v (Mactrinula) parkesiana, Hedley. 



Mactra parlcesiana, Hedley, Proc. Linn. Soc. N.S.W., vol. xxvii, 

 p. 8, pi. i, figs. 5-9, l"'902. 

 Hub. — Port Jackson, New South Wales, and Queensland (Hedley). 

 " Belongs to the Section Mactrinula'''' (Eedley). 



28. Mactra (Spisula) parva. Petit. B.M. 



Gnathodon parvum, Petit, Journ. de Conch., 1853, p. 358, pi. xiii, 

 figs. 9, 10 ; Sowerby, Ctmch. Icon., vol. xix, pi. i, fig. 6. 



Sy7ionyms and Varieties.'^ — Mactra rodrata, Keeve {non Spengler) ; 

 M. corbuloides, Deshaj'es ; M. cretacea, Angas ; Spisula producta, 

 An gas ; M. {Spisula) Jluviat His, Angas. 



Hab. — Moreton Bay ( L'etit, also Reeve for rostrafa), Port Jackson 

 (Angas and Brit. Mus. for producta), Port Stejihen (Angas for 

 cretacea), Hawkesbury River (Angas & Brazier for Jluviatilis), Port 

 Jackson and Moreton Bay (Angas for corbuloides), Victoria (Pritcliard 

 and Gatliff and Brit. Mas.). 



Notwithstanding the considerable difference in form displayed by 

 some of the so-called species mentioned in the above synonymy, 

 I agree with Hedley- and Pritchard & Gatliff^ in considering them 

 variations of one very variable species. The types of all these forms, 

 with the exception of that described by Petit, are in the British 

 Museum, and a careful examination of the hinges shows that they 

 ai'e essentially the same in all. Presuming the Moreton Bay rostrata 

 to be full-grown, the species appears to vary much in size, since 

 specimens from Port Phillip are more than double their dimensions, 

 being 26 mm. long, 20 in height, and 14 in diameter. 



Conrad and Weinkauff have erroneously placed M. corbuloides of 

 Deshayes in the synonymy of M. lateralis, Say, from the east coast of 

 the United States. In form and general external character they are 



^ For references see Pritchard & GatHff, Proc. Roy. Soc. Victoria, vol. xvi, 



p. 108, 1903. 

 - Proc. Linn. Soc. N.S.W., vol. xxvi, p. 707, pi. xxxiv, figs. 2, 3, hinge, 1902. 

 ^ Proc. Roy. Soc. Victoria, vol. xvi, p. 108, 1903. 



