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Actinomma medusa (Ehrenberg, 1844)

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Haliomma medusa, affinis forma [from Haliomma aequorea], differt radiis internis 4 interdum parumper exsertis.

["Haliomma aequorea: H. forma superficie integra hemisphaerica poris magnis perforata radiis internis 6 non exsertis. Diam. 1/34'''. Caltanisetta."(Ehrenberg, 1844; p.83)]
Ehrenberg 1844
Shell ratio is 1:30:10, however, the two inner shells are often destroyed. The third shell is of an irregular shape, thick-walled. Pores of different size and irregular outline, with about 12 pores on the half of the equator. Outside spines are nearly cylindrical, variable length and strength. Not all the spines connecting the second and third shells project outwards. About 8-11 spines; often only four or two are pronounced. Very variable species. Some forms of the species likely gave rise to neat spherical forms. Others, with an irregular surface and a reduced number of the outer spines, look very similar to some Axoprunum species.

Petrushevskaya 1975











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