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Metaheleopera ovalistoma
M. ovalistoma – after Bartos, 1963

Metaheleopera  Bartos, 1963

Diagnosis: Shell clearly narrowing towards the pseudostome, which can be seen even more clearly on the narrower sides of the shell. This narrowing creates two semi-circular lips, which are very slightly arched at the front and, viewed from above, frame a wide oval opening, which is reminiscent of the opening of Awerintzewia Schouteden, 1906. In Awerintzewia, however, the aperture is almost circular. In Metaheleopera the oval aperture is somewhat elongated in the longer axis on both sides, which is caused by the narrowing of the lips.

Metaheleopera ovalistoma  Bartos, 1963

Diagnosis: Shell consists of a thicker and pale brown-yellow colored organic layer, which is covered on top by flat mineral fragments of various sizes. The large mineral plates are clearly separated from each other and between them there are many very small, irregular pieces that are strikingly shiny. Near the aperture, the almost similarly small mineral particles form a firm and very clear delimitation of the shell gap and here the brownish mass of the basal layer of the shell is best seen. At the fundus, there are much larger and also a little thicker mineral fragments, between which detritus particles are mixed in here and there. The apertural lips line an oval gap; the lips are more visible from the narrower side of the shell than from the wider one. At the ends of the longer axis of the opening, there are much smaller and narrower gaps, which are only 2.7 µm long and as much wide. In apertural view, the aperture very nicely curved, oval.

Dimensions: Length 78-84 µm; width 52 µm; thickness 34 µm. neck 10-12 µm long; aperture 22-24 µm long, 11 µm wide.

Ecology and distribution: Dry mosses. Novoj Afon, Abchazia.

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