Dioithona oculata (Farran 1913)

Oithona oculata Farran, 1913

Oithona oculata Farran, 1913:188–189, pl. 30: figs. 8–10; pl. 31: figs. 2, 3.—González and Bowman, 1965:273–274, fig. 20h, i.—Nishida et al., 1977:139–140, fig. 13.

MATERIAL.—Numerous and from PN-13-60, PN-18-60, PN-32-200, PN-35-200, PN-50-200, PN-55-200, PN-58-200, and PN-59-200.

FEMALES.—Length range (30 specimens) 0.61–0.80 mm; Pr/Ur-1.6. Ri2P4 (Figure 1a) with both setae modified, slightly curved toward their tips; proximal seta with serrate flange on distal of medial edge; distal seta with serrate flange on distal ¼. Ri3P4 proximal seta similarly modified with serrate flange on distal . Knob near genital opening (Figure 1b) armed with anterodorsally curved spine, bearing tiny distinct teeth on posterior margin; below this spine a small point.

MALES.—Length range (30 specimens) 0.59–0.70 mm; Pr/Ur-1.5. Cph in lateral view (Figure 1d) produced into a small triangular extension near posterior ventral edge. Extension not homologous to flap previously described for O. dissimilis and O. hebes (Ferrari, 1977) or those of other oithonids in this paper; in these species posterior edge of Cph visible beneath translucent flap. Cph with a few integumental organs scattered over the lateral surface but not placed in a distinctive pattern. Organs (Figure 15a) with form of shallow pore without thickened peripheral ridge; small hair arises from the center of pore. Cph pitted with slight circular depressions, smaller in diameter than pore.