DAXIA Cuvillier and Szakall, 1949

 

 

Type species: Daxia cenomana Cuvillier and Szakall, 1949; OD.

Daxia Cuvillier and Szakall, 1949 (*865), p. 8.

Test lenticular and biumbonate to flattened, planispirally enrolled and involute, with numerous broad, low chambers per whorl, sutures arched centrally, curving back to the periph­eral angle, apertural face truncated to slightly excavated centrally for much of its height; wall finely agglutinated, simple, noncanaliculate and nonalveolar; aperture small, difficult to observe from the exterior, but thin sections show an areal opening in each septum just above the base of the apertural face, with a slightly thickened border. Cretaceous (?Neocomian, ?Aptian, Cenomanian); France.

 

Remarks: Various discussions of the aperture of Daxia have differed, probably as a result of misidentification, as other genera of this family are superficially similar in outward appearance. On the basis of specimens we have examined and sectioned from the type locality of D. cenomana, at Audignon, and from Ile Madam, Charente Maritime, France, specimens illustrated by Neumann (1965, *2245, pl. 1, figs. 1, 2, and 5-7) are Mayncina orbignyi rather than D. cenomana. True Daxia is len­ticular and biumbonate with a relatively acute periphery and has a single areal opening; M. orbignyi is thicker, distinctly biumbilicate, and somewhat inflated from the vicinity of the um­bilicus for about half the distance to the periph­ery, and the aperture is multiple. Neumann (1965, *2245, p. 91, footnote 3) quoted a letter from Maync that indicated a probable multi­ple aperture in Daxia; this also appears due to a similar misidentification of Mayncina as Daxia. Maync (1972, *2082, p. 357) described a single areal aperture for Daxia.