Conescharellina longirostris Silén, 1947a

Martino, Emanuela Di, 2023, Scanning electron microscopy study of Lars Silén’s cheilostome bryozoan type specimens in the historical collections of natural history museums in Sweden, Zootaxa 5379 (1), pp. 1-106 : 83-84

Conescharellina longirostris Silén, 1947a

Conescharellina longirostris Silén, 1947a: 41 , text-figs 25, pl. 1, figs 7, 8.

Material examined. Syntypes: SMNH-Type-4605 (two colonies; Fig. 45F–H ), Java Sea, Noordwachter Island, Malay Archipelago ; 2°56'S, 107°55'E; depth 15–18 m. Leg. C. Aurivillius 1891 . Additional material: SMNH-220511 ( Fig. 45A–E ), a third colony included in the same box as the syntypes, morphologically distinct from C. longirostris and now registered as Conescharellina sp.

Remarks. As for Conescharellina brevirostris , also for C. longirostris , the number of colonies available in the syntype series is different from the number of colonies reported in Silén (1947a), i.e. three colonies available in the collection versus five colonies reported in the original publication. Of these, two colonies have well developed peristomes as stated in the original description ( Fig. 45F–H ), one colony does not ( Fig. 45A–E ). Unfortunately, the two colonies with prominent peristome are poorly preserved, preventing meaningful description and observation of the main diagnostic feature of this species, i.e. the large latero-oral avicularium with elongate rostrum associated with each zooid (see Silén 1947a, text-fig. 25). In addition to the absence of peristomes, the remaining colony also lacks the large latero-oral avicularium typical of C. longirostris , and it differs from C. laevis in the shape of the orificial sinus (i.e. bowl-shaped versus U-shaped). Table 40 gives the zooidal measurements for this colony, reported as Conescharellina sp. Colony size is 1.585 × 1.450 mm. This specimen is now registered under the catalogue number SMNH-220511.

Poor preservation of the remaining two colonies prevented size measurements.

Genus Crucescharellina Silén, 1947a

Figures

FIGURE 45. A–E. Conescharellina sp. SMNH-220511, Java Sea, Malay Archipelago. A. Lateral view of the colony. B. Group autozooids and interzooidal avicularia. C. Close-up of an orifice. D. Close-up of avicularia. E. Close-up of the apical cone with kenozooids and avicularia. F–H. Conescharellina longirostris Silén, 1947a SMNH-Type-4605, Java Sea, Malay Archipelago. F. Apical view of a colony. G. Apical view of some zooids showing a well-developed proximolateral peristome. H. Antapical view of a colony. Scale bars: A, F, H = 500 µm; B, E, G = 200 µm; C, D = 100 µm.