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Xiphatractus spumeus Dumitrica, 1973

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Xiphatractus spumeus n. sp. Dumitrica 1973 p. 833; pl. 20, fig. 9

Description: The skeleton consists of three oval concentric shells disposed at about equal distance from one another and connected by numerous radial beams. The innermost shell is pear-shaped with large circular pores. The median shell is oval, with large, circular, hexagonally framed pores. The outermost shell is oval, rough, and is armed with two dissimilar, short, pyramidal, polar spines. The pores are large, circular, equal, and hexagonally framed. In the aged specimens, the pores are more or less closed by a lattice network originating in several centripetal ingrowths from the pore-walls.


Dimensions: Equatorial diameter of the innermost shell is 32 to 35μ; of the median shell it is 63 to 67μ, and of the outermost shell it is 105 to 118μ. Polar diameter of the outermost shell is 110 to 130μ.


Remarks: Although there is a striking similarity between the innermost and median shells of this species, and the young shells of Druppatractus variabilis, they are independent taxa. X. spumeus is generally rare in the Mediterranean samples, its frequency reaching several percentages (up to 7%) only at a few levels.
Dumitrica 1973


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