242 146 



Chione (Omphaloclathrum) marica L. (Sow.). 



(PI. V, Figs. 1-4). 

 Venus marica, Linn.kus. Sowerby, Thesaurus Concliyl., II, p. 719, No. 47, pi. 157, fig. 108 



Between Koh Riot and Koh Mesan, 3-5 fathoms, sand ('/a). N. of Koh Kalidal, 

 4 -5 fathoms, coarse sand (2). W. of Koh Kul, 15 fathoms, mud (1). 



Long. 8 — 19 mm. 



Distribution ? 



Edg. Smith says in the report on the Lamellibranchiata of the Challenger 

 Expedition (p. 125) "This species {Venus (Chione) marica L.) is so well known that 

 it is unnecessary to give further references than those above mentioned." This may 

 be true as regards the name, because from as far back as the times of Linné and 

 Chemnitz it has constantly been recorded and mentioned from many localities all 

 over the globe; but a comparison of the descriptions and figures given by Linné, 

 Chemnitz, Sowerby, Reeve and others leaves an impression of great uncertainty 

 with regard to the characteristics and limits of the species. For instance, it appears 

 to me that Linné-Chemnitz's species can scarcely be identical with Sowerby's Ch. 

 marica, Thes. Conchyl. fig. 108 (Edg. Smith's species Ch. recognita is undoubtedly 

 also frequently confused with Ch. marica). All the individuals from the Gulf of 

 Siam agree precisely with Sowerby's figure 108, but how far that is identical with, 

 or is a form of Linné's Ch. marica is perhaps doubtful. I have given a figure of 

 the specimens from the Gulf of Siam to fix the form for future comparisons. The 

 specimens from Moltke's collection, from which Chemnitz had his figures 282 — 84 

 made (PI. 27 in the "Conchylien Cabinet". Figs. 285— 86 scarcely belong here), exist 

 no longer in the Moltke collection included in the Zoological Museum of the 

 University of Copenhagen, so I have not been able to compare Chemnitz's specimens 

 with mine from the Gulf of Siam. Sturany' is inclined to regard "Venus Romeriana, 

 Issel," from the Red Sea, as a young form of Ch. marica L. 



Chione (Omphaloclathrum) recognita, E. Sm. 



Venus (Cliione) recognita, Eud. Smith, Keport on the Lamellibranchiata of the Challenger Expedition, 

 1885, p. 125, pi. 3, fig. 5. 

 — Marica, Reeve p. p., Concholog. icon., XIV, 1863, Venus, fig. 104 a (non 104 b and c). 



Koh Kahdat, sand, 1—5 fathoms (70). N. of Koh Kahdat, 4-5 fathoms, sand (14). 

 Koh Mak, sandy coast (-/a). S. of Koh Mak, 5-6 fathoms (2). W. of Koh Kut, 15 

 fathoms, mud (4). 



Long. 6-5 — 20 mm. 



Long. 20 mm., alt. 15 mm., crass. 10 mm. 

 — 17 mm., — 135 mm., — 85 mm. 



Distribution:— Suvativa Atoll (Maldive Archip.), Philippines. — Mast Head 

 Reef, Queensland (Hedley). 



' Lamellibranchiaten d. Rothen Meeres, 1899, p. 27. 



