79 175 



Diplodonta conspicua, Smith. 



Diplodonta conspicua, Edg. Smith, Report oii the Lamellibranchiata of the Challenger Exped., 1885, 

 p. 198, pi. 14, fig. 11. 



Sound of Koh Chang, 5 fathoms, soft chiy (Va). Koh Kahdaf, 1 fathom, sand ("^/s). 

 S. of Koh Kahdal, 8—10 fathoms, mud {-'l-i). Between Koh Kut and Koh Kahdat, 

 6—10 fathoms, clay mixed with sand, and shells (^^/a). N. of Koh Kut, 10 fathoms, 

 mud ( Vs). W. of Koh Kut, 15 fathoms, mud (^/s). W. of Koh Kut, 30 fathoms, 

 sand and mud (';). 



Long. 2 — 11 mm. (long. 11 mm., alt. lOS mm., crass. 7 mm.). 



Distribution: — Flinders Passage, Torres Strait. 



Smith's specimens from the Challenger Expedition have a length of only 

 4 mm., while the specimens from the Gulf of Siam may measure as much as 

 11 mm. in length. Edg. Smith has overlooked (or perhaps they were but in- 

 distinctly visible in his small individuals) that besides the characteristic denticula- 

 tions on the inner front margin there also occur 3—5 corresponding denticles on 

 the inner hinder margin, at the same level as those on the front side. Smith 

 mentions the presence of 5 to 6 distinct denticles on the inner front margin, this 

 is certainly often the case, but most frequently 7—9 denticles occur both on 

 larger and smaller specimens. 



Note. It is strange how Diplodonta globosa, Forskål, has been misapprehended, 

 and confusion thereby brought into the literature, although both Forskål and 

 Chemnitz have given good diagnoses and figures of it. Forskål's original specimens, 

 contained in Spengler's collection, on the basis of which Chemnitz wrote his de- 

 scription, are now preserved in the Zoological Museum of the University of Copen- 

 hagen. In the following I shall give a summary of the views, partly erroneous, of 

 the different authors, concerning this species and its synonj'my : — 



Venus globosa, Forskål, Descript. animal, quæ in itin. orient, observ., 1775, p. 122, No. 53. 

 — — — Chemnitz, Conchyl., Cabin., VII, 1784, p. 36, pi. 40, figs. 430-31. 



LiiciiKi sp., Savignv, Iconographie d. Moll, de l'Egypte, pi. 8, fig. 7 = Dipl. globosa. Forsk. In the explana- 

 tion of the figures Audolin erroneously names this species Lucina edentula. Vaillant Journ. 

 de Conchyl., XIII, 1865, pp. 124 — 125) and, on his authority, Issel (Malacologia d. Mar Rosso, 

 1869, p. 358 refer Savigny's figure to Diplodonta Savignyi, Vaill. E. v. Maistkns (Vorderasiat. 

 Conchylien, p. 103) says in regard to this point: "Frischer und Issel haben übrigens Unrecht, 

 die Abbildung in der Description de lÉgypte PI. 8, Fig. 7 hierher zu citiren, da diese nach 

 der Zeichnung der Muskeleindrücke eine richtige Lucina darstellt, ohne Zweifel L. globosa, 

 Forsk." Vaillant's Diplodonta SaDigniji, according to ray opinion, is identical with Diplodonta 

 globosa; on the other hand Vaillants Lucina globosa can scarcely be Chemnitz's (Forskål's) 

 species of this name. 



— globosa, Chemnitz, Gray, The Annals of Philosophy, New Ser. IX, 1825, p. 136. 



— Globosa, — Hanley, III. Catal. rec. biv. shells, p. 78. 



Diplodonta bullata, Dunker, Novitates Conchologicae. II, Meeres Conchyl., p. 76, No. 83, pi. 26, figs. 1 —3 



= Dipl. globosa. Forsk. 

 Lucina globosa, Forskal, Pfeiffer in Martini u. Chemnitz, Conchyl. Cabin., XI, 1 Abth., 1869, p. 267, 



pi. 20, figs. 11-12. 



— (Loripes, globosa, Chemnitz, Issel, Malacol. del Mar Rosso, 1869, p. 85, No. 107. 



— {Anodontia) globosa. Forskal, v. Martens, Mollusken d. Maskarenen u. Sej'chellen, 1880, p. 146. 



(v. Martens regards here erroneously, L. pita, Reeve (Conchol. icon., Sp. 24), as a sj'nonym of 

 the present species. Reeve (Conchol. icon.) says expressly regarding the species figured on PI. V, 

 (Sp.21 — 24 , that they have "the hinge toothless," which is not at all the case in L. globosa, Forsk. 

 The fact that v. Martens refers this species to the subgenus Anodontia (as also the observa- 

 tions he makes elsewhere regarding this species proves that his view of it is wrong, and that 

 he has overlooked what is expressly stated in Chemnitz's diagnosis: "Im Schlosse stehen in 

 jeder Schale nur zween Zähne."). 



