Conescharellina d’Orbigny 1852

Bock, Philip E. & Cook, Patricia L., 2004, A review of Australian Conescharellinidae (Bryozoa: Cheilostomata), Memoirs of Museum Victoria 61 (2), pp. 135-182 : 142-144

Conescharellina d’Orbigny 1852

Conescarellina [sic] d’Orbigny 1852: 447. Conescharellina .— Canu and Bassler, 1917.— Waters, 1919: 93.—

Canu and Bassler, 1929: 480.— Silén, 1947: 33.— Harmer, 1957:

726.— Gordon, 1989: 81.

Type species. Conescharellina angustata d’Orbigny, 1852 , subsequent designation by Waters, 1919: 93. [ Canu and Bassler (1917) had earlier incorrectly indicated C. cancellata ( Busk, 1884) , see Harmer (1957: 726)]. The mis-spelling of the name as Conescarellina occurs only in the genus heading of d’Orbigny (1852: 447): all other spellings of the name are as Conescharellina . Conescharellina angustata was included in Batopora by Reuss (1867: 224).

Description. Colony conical, with autozooids appearing to be in radial series, either placed in rows alternating with avicularia, or in quincunx with intervening avicularia. Cuticular roots arise from circular or crescentic skeletal pores, concentrated in the adapical region in some species. Orifices with an antapical sinus, often with raised lateral peristomes. Avicularia adventitious and interzooidal, usually budded in distinct patterns, with acute or rounded mandibles, slung on a bar, that often has one or more palatal ligulae. Ovicells hyperstomial, prominent, derived from an adapical pore, with thinly calcified ectooecium and entooecium. Central part of colony cone occupied by a core of small kenozooids (cancelli), often accompanied by avicularia, that may cover the antapical surface late in as togeny.

Remarks. C. angustata was described by d’Orbigny (1852: 447, pl. 714 figs 14–16) from the Philippine island of Basilan (approx. 6°50'N, 122°E, in the Celebes Sea). The figured colony (fig. 15) was an elongated cone with 8–9 apparently radial series of zooids forming costules. The orifices are raised, circular-to-oval, each with an asymmetrically arranged pair of pores adapically, and a single series of “special” pores alternating with the zooid orifices in a radial depression. D’Orbigny noted that the orifices were in quincunx, and figured the antapical surface (fig. 16) showing five alternating series of proliferal and subproliferal zooids, with no central cancelli. D’Orbigny noted this particularly, comparing it with the antapical side of C. dilatata (see below). In view of the relatively large size and possible maturity of the type colony (height approximately 2.5 mm), it is unusual in Conescharellina for cancelli to be absent. In fact, this is characteristic of Trochosodon .

A scanning electron micrograph of the putative type specimen, from the Muséum Nationale d’Histoire Naturelle, Paris, has been provided by Drs D.P. Gordon and P.D. Taylor. It resembles d’Orbigny’s figure 15 in its elongated conical shape and radial series of zooid orifices. The adapical region is less regular than the figure, and there are fewer zooid series but this may be the result of damage.The rounded secondary orifices, almost all of which have an adapical pore, are similar to those figured but the additional pores shown near the orifices are not present. D’Orbigny figured a radial series of pores in the depression between zooid series, that were lateral to the adapical edge of the adjacent orifices. Avicularia occupy a similar position in the micrograph of the specimen but are far larger and twice as frequent. These avicularia are small and rounded with a delicate, simple bar. The orifices of fig. 15 are secondary and show a slightly raised peristomial rim; a few of those in the micrograph also show a sunken primary orifice with a rounded sinus. The specimen of C. angustata resembles some of the more elongated colonies of C. diffusa . These differ in their proportionally larger avicularia and the presence of numerous lunate root pores, that are absent from C. angustata . Waters (1905: 9, pl. 1 fig. 7) examined the type material of C. angustata and gave a figure of the specimen from Basilan. This does not show the entire colony but only a formalised representation of four oval orifices and a single antapical avicularium. Later, Waters (1919: 93) indicated C. angustata as type species of Conescharellina , without comment. He also (1921: 419, pl. 30 fig. 18) figured but did not describe a specimen “from China, sent to me thus named by Jullien” as C. angustata . This colony was also conical and very elongated, with raised “costules” of radial rows of oval secondary orifices separated by adapically placed pores. One elongated sinuate, perhaps primary, orifice was figured, and small scattered pores among the orifices may have represented avicularia. Unlike the type specimen, the adapical region was occupied by extrazooidal or kenozooidal calcification. The figure is otherwise similar to that of d’Orbigny’s C. angustata , with “costules” of secondary orifices that are more elongated and with “pores” less regularly spaced. Harmer (1957) was doubtful that the three Siboga collection specimens from East Java, that he nevertheless assigned to C. angustata , were identical with d’Orbigny’s species. These colonies were not elongated; the primary orifices were patent, with little or no peristome, and were relatively wide with a rounded sinus. These specimens do not appear to be conspecific with the type specimen. D’Orbigny (1852: 447) also introduced but did not figure Conescharellina dilatata from “Manille et détroit de Malacca ” [sic]. It differed from C. angustata in its greater width (“ensemble plus large”) and in the presence of “un espace poreux” (presumably of cancelli) on the antapical surface. Waters (1905: 9, pl. 1 fig. 6) gave a semidiagrammatical figure of two zooid orifices from a specimen of C. dilatata from d’Orbigny’s collection from Manila. There were “two species in the tube” but he did not indicate which of these he regarded as C. dilatata . As before, only examination of the type material can elucidate fully the characters and relationships of this species. However, it is obvious that d’Orbigny’s C. angustata is closely similar to, and congeneric with, many of the other taxa subsequently referred to Conescharellina but description of its specific characters must await examination of the type specimen.

Species recorded from Australia but not recognised in the material examined here

Conescharellina philippinensis (Busk, 18540 and C. cancellata ( Busk, 1854)

Lunulites philippinensis Busk, 1854 and L. cancellata Busk, 1854 were described and figured by Busk (1854: 101, pl. 113 figs 1–3 and 4–7 respectively) from the Philippines. They are obviously species of Conescharellina but the characters described and figured are not sufficiently clear to allow their recognition and identification with other material with any certainty. It has been possible to examine specimens from the “ type suites” of L. philippinensis and L. cancellata but it must be emphasised that until all Busk’s specimen suites have been revised, little may be concluded as to the nature and the identity of specimens later reported under these names. According to Waters (1921: 419), Busk’s specimens in the British Museum collection confused both species and included at least two additional species. Harmer (1957: 742) did not, however, agree with all Waters’ conclusions. The “ type ” slide of L. philippinensis (BMNH 1854.11.15. 150) originally included five colonies. Two of these have been lost in the past; one was remounted as an additional slide and labelled in Kirkpatrick’s hand. This very worn, separated colony may be the original of Busk’s figure (1854: pl. 113 fig. 2). The other specimens do not appear to have been figured, although all three seem to be conspecific. The specimens are all worn and show little detail. Two are flat and are less than 2 mm in diameter. They include approximately five quincuncial generations of zooids and each whorl has nine to ten zooid orifices. The marginal peristomes are slightly prominent and tubular; the primary orifices cannot be seen. Small rounded pores, inferred to have been avicularia, are interspersed randomly among the zooid orifices and the antapical surface has a central cancellate area. In both the larger colonies, the centre of the adapical surface has two prominent rounded “bosses”, that are illustrated in Busk’s pl. 113, fig. 2. It is not possible to recognise this species, either among those described from the Philippines by Canu and Bassler (1929) or in the Australian material examined here. The “ type ” slide of L. cancellata (BMNH 1854.11.15.151) includes four specimens that are in a better state of preservation. The originals of Busk’s pl. 113, figs 4–7 are recognisable; an additional large, worn, unfigured colony, that does not seem to be conspecific, is present ( Brown, 1958: 82). The figured colonies are distinctly domed; the largest, that is less than 2 mm in diameter, includes approximately seven quincuncial zooid generations and nine to ten zooids per whorl. The peristomes are only slightly raised and circular; the primary orifices are visible and are rounded with a short, wide, almost semicircular sinus. Traces of an adapical pore are present in a few zooids. Small oval avicularia, with a delicate, simple bar, occur somewhat irregularly among the zooid orifices. No root pores are visible; the antapical surface has a central cancellate area. This species was apparently not among the other Philippine forms described by Canu and Bassler (1929) and has certainly not been recognised among the Australian specimens examined here.

Waters’ (1921) account of L. cancellata is not at all clear. He remarked “specimens from Busk’s own collection so named are C. angustata d’Orb. ” Harmer (1957: 742), when discussing C. crassa , seems to have mistaken Waters’ (1921) reference to C. angustata , as describing part of the type material of L. cancellata . A specimen in Busk’s collection from the Sea of Japan (BMNH 1899.7.1.1276 labelled Lunularia cancellata ) is narrowly conical, with seven to eight radial series of orifices and five to six zooid whorls. Zig-zag series of small oval avicularia alternate with the orifice series; these also occur on the antapical surface. The colony somewhat resembles d’Orbigny’s C. angustata and may be the one mentioned by Waters. Waters (1921) also stated that the specimens he described “from New South Wales” (i.e. in 1887) “then called cancellata by me are seen to be philippinensis .” Both names have been used for several Australian records; references to Recent material assigned to these species are discussed below under C. diffusa and C. obscura .

It is unfortunate that little of the previously described Tertiary material is extant. Various combinations and spellings of C. cancellata having been quoted, particularly for specimens from the Tertiary, by Waters (1881; 1882a; 1882b) and by MacGillivray (1895). Maplestone (1904) tabulated several additional fossil localities, including Campbells Point, Mitchell River and Lake Gnotuk, together with his own observations of material from Mornington. Unfortunately, Maplestone’s specimens are not extant, and therefore his concept of fossil B. cancellata and B. philippinensis must remain unknown. He also listed B. elegans Waters (= Bipora flabellaris ), from Jimmys Point, that has otherwise not been reported as a fossil, and therefore seems unlikely to be this species. MacGillivray (1895: 89, pl. 12 fig.2) reported “ Bipora philippinensis ” from the Tertiary of Schnapper Point and Muddy Creek, Victoria. His specimen from Muddy Creek is extant (NMV P27728). It is a fairly flat colony, with quincuncial zooid orifices with a small sinus and scattered avicularia. The antapical surface has a large cancellated area. This specimen appears to be referable to the fossil species described here as Conescharellina macgillivrayi sp. nov. Waters (1881) mentioned Recent specimens of B. cancellata from Torres Strait but no fossil examples. However, he appears to have believed that he had specimens from the “Curdies Creek” locality, as he mentioned them ( Waters, 1882a) in connection with the “better preserved” material he had from Bairnsdale, Victoria ( Waters, 1882b: 512, pl. 22 figs 10, 11, as Lunulites cancellatus ), that he figured showing the orifice and surrounding avicularia. These illustrations suggest that the species may also have been Conescharellina macgillivrayi . Whitelegge (1887: 341) listed C. cancellata , remarking that he had several fossil examples from Muddy Creek, Victoria, that might be identical with the species recorded by Waters (1882b) but that in C. cancellata and C. philippinensis “the identity can only be definitely settled by comparison with the types ”. Bipora cancellata was recorded by MacGillivray (1895: 89, pl. 12 fig. 1) from Bairnsdale; he noted that it was often difficult to distinguish it from B. philippinensis . His specimen (NMV P22727) is a conical colony with orifices arranged in radial series. The primary orifice has a fairly wide, rounded sinus and is flanked antapically by a pair of small, rounded avicularia. The antapical surface has very few cancelli. His specimen resembles others from Bairnsdale, and is discussed here under Maplestone’s Recent colonies of C. diffusa . Colonies from the Miocene of Victoria and South Australia are numerous and diverse; four species, C. ocellata , C. macgillivrayi , C. humerus and C. aff. diffusa are described below.

The ovicells of C. cancellata were mentioned, in passing, by Levinsen (1909: 310, pl. 23 figs 8a, b), who illustrated small, globular ovicells with marginal pores and an oval zooid orifice with an adapical pore. Three small rounded avicularia surrounded the ovicelled zooid orifice. Levinsen did not give any details of the provenance of the specimens illustrated and the information given is insufficient for identification of the species.