Hoogenraadia sylvatica
H. sylvatica – from Vucetich, 1973

Hoogenraadia sylvatica Vucetich, 1973

Diagnosis: Test ovoid; pseudostome with a highly developed visor. In ventral view, the visor completely conceals the aperture and forms a sinuous line that extends to both sides of the test. The region between the lower edge of the visor and its lateral extensions is slightly concave. The pseudostome can be seen only by placing the test in lateral position and somewhat tilted toward the region of the visor. The test is quite transparent, and yellowish-brown, embedded in a hyaline cement with exogenous mineral particles larger in the body than in the visor.

Dimensions: Length 82-93 µm; width: 60-70 µm; thickness: 58-68 µm.

Ecology: Argentina, Punta Lara jungle

Remarks: The Argentine species, according to its morphology, is closest to H. cryptostoma, which is distinguished by the more pronounced cryptostome, the concavity in the ventral region and a smaller size (approximately 1/2 the size of H. cryptostoma).

Recent posts

Difflugia australis

D. australis after Playfair, 1917 Difflugia australis (Playfair, 1917) Gauthier-Lièvre et Thomas, 1958 Syn.: Difflugia bacillariarum var. australis Playfair 1917 Diagnosis: Test broadly ovate, with

Read More »

Difflugia baradlana

D. baradlana after Varga, 1963 Difflugia baradlana Varga, 1963 Diagnosis: Test ovoid with a very small neck which is about 1/4 of the test length.

Read More »

Difflugia angelica

D. angelica after Gauthier-Lièvre et Thomas, 1960 Difflugia angelica Gauthier-Lièvre et Thomas, 1960 Diagnosis: Test spherical, slightly mammillated. Pseudostome regularly lobed like a star with

Read More »

Difflugia algaephila

D. algaephila after Decloitre, 1977 (l) and Chardez (1980) Difflugia algaephila Decloitre, 1977 Diagnosis: Test ovoid, neatly pointed, with oblique round pseudostome. Dimensions: Length 73-75

Read More »

Difflugia key spherical

Spherical tests Tests that are more or less spherical, some with a collar, but all without spines or other outgrowths. The aperture or pseudostome is

Read More »

Difflugia key compressed

Compressed tests Compressed tests are more or less oval or elliptical in cross-section. The aperture is round or oval or even lobed. This group has no

Read More »