Stoliczkella crenatula ( Stoliczka, 1862 ) Zágoršek & Gordon, 2014

Zágoršek, Kamil & Gordon, Dennis P., 2014, Revision of the Oligocene bryozoan taxa described by Stoliczka (1862), with the description of a new genus of Bryocryptellidae, Geodiversitas 36 (4), pp. 541-564 : 554

Stoliczkella crenatula ( Stoliczka, 1862) n. comb.

( Fig. 5 A-F)

Eschara crenatula Stoliczka, 1862: 87 , pl. 2, fig. 8.

MATERIAL EXAMINED. — Five syntypes, registered as 2010/0259/0007. Stoliczka’s (1862) illustration does not correspond exactly to any of the specimens labelled as Eschara crenatula , hence the illustrated specimen may be lost, or Stoliczka inadvertently illustrated a different species. Ŋe selected lectotype (designated here) is the best-preserved of the syntypes and is depicted as Figure 5A herein.

DESCRIPTION

Colony erect, bilamellar, flat, autozooecia opening on both faces. Autozooecia of similar shape to S. subovata n. comb., with combined peristomial aperture/suboral avicularium complex proportionately larger, occupying a considerable part of frontal surface. Frontal shield smooth, imperforate except for small, sparse, areolar-septular pores in the margins typically paired proximally. Secondary calcification increases convexity of frontal shield. Two areolar-septular pores situated on the proximal margin of the autozooecia, sometimes indistinct. ‘Primary aperture’ deeply immersed beneath peristomial aperture, the rim of which embraces the suboral avicularium so that the paired spiramina and broken avicularian chamber often appear as three holes of equivalent size. Median process separating spiramina shorter than in S. subovata n. comb. Oral spines absent. Suboral avicularium circular, with no trace of crossbar remaining in any zooecium. Ooecium deeply immersed, recumbent on distal zooecium, ectooecium imperforate, typically mostly concealed by secondary calcification. Adventitious avicularia rare on frontal shield, large, with long rostrum tapering laterally. Vicarious avicularia situated on the margin of colony, as large as autozooecium, with rounder rostrum and drop-like aperture.

REMARKS

Ŋe type material examined cannot be fractured and the interior of the frontal shield and aperture have not been observed. From frontal view we infer that the construction of the spiraminal complex is similar to that in S. subovata n. comb. Stoliczkella crenatula n. comb. differs from S. subovata n. comb. in having shorter autozooecia, smaller suboral avicularia and larger adventitious avicularia with a pointed rostrum.

Figures

FIG. 5. — Stoliczkella crenatula (Stoliczka,1862),n. comb.; A, general view of lectotype; B, autozooecial apertures with suboral avicularia smaller than those in Stoliczkella subovata n. comb. (cf. Fig. 3F); C, partly preserved ooecium; D, older stage of colony development showing secondary calcification; E, autozooecia with deeply immersed ooecia and small avicularia; F, autozooecial aperture with proximal depression accommodating areolar pores. Scale bars: A, D, 1 mm; B, C, E, F, 100 μm.