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Lampromitra petrushevskae Dumitrica, 1973

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Shell is flat, conical and formed of two segments. Cephalis is smooth, with rounded cupola, and with numerous irregular, small, subcircular pores. Dorsal and primary lateral spines are extended into the thoracic wall to form three strong straight ribs. Apical and vertical spines penetrate through the cephalic wall giving rise to short spines. Two other small cephalic spines may arise on one side and another of the cephalis from the two arches connecting the lateral spines with the apical one. Thorax broad conical with irregular polygonal pores, which are much larger in the middle part than in the upper or lower part. Collar stricture is not well defined, but the cephalis is distinguished from the thorax by its small pores. Peristome has a double coronal of short conical divergent spines, the upper obliquely ascending, the lower obliquely descending. Between them there is a single row of pores. Spines are simple or thorny.

Dimensions: Diameter of thorax without spines is 180 to 190μ.

Remarks:
The description of this new species is based on eight specimens found in 128-3-5, 20-25 cm, and in 127-14-4, 112-115 cm. It is fairly closely related to L. schulzei (Haeckel, 1862), from which it differs by having a much smaller number of thoracic coronal spines, and only one row of coronal pores. It seems also rather similar to Amphiplecta callistoma (Haeckel, 1887).

Picture: Figures 6, 7. Lampromitra petrushevskayae n. sp., holotype, in apical and lateral view. 128-3-5, 20-25 cm, X230.
Dumitrica 1973


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