Stephanotheca victoriensis , Reverter-Gil, Oscar, Souto, Javier & Fernández-Pulpeiro, Eugenio, 2012
treatment provided by
Stephanotheca victoriensis n. sp.
( Figs 31–35View FIGURES 31 – 35; Table 4)
Schizoporella ambita Waters, 1889: 11 (part: only material from Victoria).
Not Schizoporella ambita Waters, 1889: 11 (part: material from Naples and Green Point).
Material examined. Holotype: MM 2937. Port Western, Victoria, Waters. Coll. Paratype: MM 4172; same locality as holotype.
Etymology. The two colonies of the present species were collected in Victoria, southeast Australia.
Description. Colony encrusting, unilaminar, forming broad irregular crusts. Autozooids in regular linear series, sometimes alternating; often subrectangular, large, separated by fine sutures. Frontal shield flat or slightly convex with a slightly granular surface, perforated by small, circular pores situated in depressions demarcated by slightly raised ridges. Secondary calcification producing scattered granulation; marginal pores becoming areolar in older zooids. Periorbital region imperforate, somewhat swollen, marked with thick nodules. Primary orifice orbicular, wider than long, its distal edge projecting distally; a wide, shallow sinus occupies half of the poster; condyles small, oval, serrate only along their inner half. Oral spines absent. Suboral avicularia nearly constant; oval, small, with slender, complete crossbar; semi-elliptical mandible proximally directed. Distance to orifice equal to avicularium length. Ovicell globular, prominent, frontally flattened, with an almost even surface; ectooecium with a wide arch of rounded pseudopores and some scattered frontal pseudopores. Maternal zooids with dimorphic orifices, almost circular, large and with shallower sinus. Ovicell opening inclined at an angle, formed by the concave proximal margin of the ooecium, overarching the primary orifice and extending to its proximolateral corners. Ancestrula unknown.
SD, Standard deviation; N, number of measurements.
Remarks. Two samples in the Waters Collection, labelled as Schizoporella ambita , come from Port Western (Victoria, Australia); one of them was reported in the original description by Waters (1889). This material shows important differences from the type material of S. ambita , viz. fewer and smaller pseudopores and an imperforate rim around the orifice, thick and with nodules; the frontal surface is covered by granulations; the primary orifice is wider, with denticulated condyles in their inner half; and the avicularium is longer, flattened and more distant from the orifice. The opening of the ovicelled zooid is also dimorphic, almost rounded, but none closed by the operculum has been seen, perhaps because of drying. Ovicell surface morphology also differs — it is globular and prominent, with an almost even surface without a nodular crown, and a wide frontal arch of pseudopores. This species is provisionally included in Stephanotheca .
|Adventitious avicularium length||0.079||0.0037||0.073||0.085||16|
|Adventitious avicularium width||0.060||0.0025||0.056||0.065||16|
|Ovicell orifice length||0.136||-||-||-||1|
|Ovicell orifice width||0.162||0.0040||0.158||0.166||3|
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