Stenostomum simplex Kepner & Carter, 1931

Noreña, Carolina, Damborenea, Cristina & Brusa, Francisco, 2005, A taxonomic revision of South American species of the genus Stenostomum O. Schmidt (Platyhelminthes: Catenulida) based on morphological characters, Zoological Journal of the Linnean Society 144 (1), pp. 37-58 : 49

Stenostomum simplex Kepner & Carter, 1931

( Fig. 3C )

Description: Individuals with 2–4 zooids, 0.7–0.8 mm long. Body cylindrical. Anterior end tapering. Presence of lateral constrictions in the ciliated pit regions, and at the caudal edge of the posterior lobes. Small lateral ciliated pits. Rounded posterior end, without an intestine-lacking region. Ciliated epithelium frequently with sparse longer sensory cilia. Homogeneous rhabdites.

Anterior brain lobes separated into small independent masses (‘metamerics’). A pair of internal lobes associated with the posterior lobes (trilobate brain after Marcus, 1945a). Spherical nerve commissure. A pair of light-refracting bodies formed by a single naked sphere, with no vesicle (type 3), associated with the posterior brain lobes.

Small, axially elongated oral pore. Type a pharyngeal glands. No excretophores. Nephridiopore terminal.

Distribution: Virginia, USA ( Kepner & Carter, 1931; Kolasa, 1991); São Paulo, Brazil ( Marcus, 1945b); Finland? ( Lanfranchi & Papi, 1978).

Figures

Figure 3. A, Stenostomum paraguayense. B, S. rosulatum. C, S. simplex. D, S. tenuicauda. E, S. uronephrium. F, S. virginianum. Scale bars = 200 Mm.