Raphidiophrys ovalis (Dürrschmidt, 1985) Siemensma and Roijackers, 1988
Diagnosis: scales ovate, with inflected, sharp-edged, narrow rims; scale size 6.4-12.7 X 3.0-6.4 µm, with a L/B-ratio of 1.4-2.3; number of septa along the border varying from 65-70 per 10 µm.
The size of the scales is larger than the type, but this species shows a large variation in scale size within a specimen (Nicholls and Dürrschmidt 1985; Fig. 45). Calculations derived from that photomicrograph showed a range between 4.4 and 9.0 µm. The shape and structure of the scales in my specimens resemble closely that of the type.
The upper plate of the scale is very fragile and sensitive to drying. Notwithstanding the weight of other scales, they easily collapse or split along the septa.
Scales of R. ovalis were published by Siemensma (1981) under name of R. intermedia and were considered by Nicholls and Dürrschmidt (1985) to belong to a subspecies of R. orbicularis elegans. The distinctly ovate shape and the fragile structure of these scales, strongly different from all other known Raphidiophrys, justify the recognition at species level.