Paracaudina chilensis (Müller, 1850)

Figures 1c, 7, 8, 12b

Molpadia chilensis Müller, 1850: 139 .— Müller, 1854: pl. 6 fig. 14, pl. 9 fig. 1.— Semper, 1868: 233.— Théel, 1886: 55.

Microdactyla caudata Sluiter, 1880: 348–351, pl. 6 fig. 1, pl. 7 figs 1–6.

Caudina ransonnetii Marenzeller, 1881: 126–127, pl. 4 figs 5, 5A.— Ludwig, 1883: 158–159.— Lampert, 1885: 210.— Théel, 1886: 54.— Ludwig, 1891: 354.— Mitsukuri, 1912: 261–262, pl. 8 fig. 76.

Caudina caudata .— Ludwig, 1883: 159. (synonymy with Caudina chilensis (Müller) by H. L. Clark 1908)

Caudina coriacea .— Théel, 1886: 47, pl. 3 fig 4a–c. (non Caudina coriacea Hutton, 1872)

Caudina rugosa R. Perrier, 1904: 16 .—R. Perrier, 1905: pl. 4 figs 10–12. (synonymy with Caudina chilensis (Müller) by H. L. Clark 1908)

Caudina pigmentosa Perrier, 1904: 16–17 .— Perrier, 1905: pl. 4 figs 1–9. (synonymy by H. L. Clark 1935)

Caudina contractacauda H. L. Clark, 1908: 38–39, 173, 177, 178, pl. 9 figs 9–13. (synonymy by H. L. Clark 1935)

Caudina chilensis .—H. L. Clark, 1908: 173, 175–176.— Hozawa, 1928: 361–378, pls 14–17.— Ohshima, 1929: 39–45.

Pseudocaudina chilensis .— Heding, 1931: 283.

Pseudocaudina ransonnetii .— Heding, 1931: 283.

Paracaudina chilensis .— Heding, 1933: 127–142, pls 5–8.—H. L. Clark, 1935: 267–284.— Deichmann, 1938: 383–384, fig. 15.— Pawson, 1969: 139–140.—A. M. Clark and Rowe, 1971: 184–185.— Pawson, 1977: 119 (part).— Cannon and Silver, 1986: 40.— Rowe and Gates, 1995: 264.—Liao and Clark, A. M., 1995: 518–519, fig. 316.— Lane et al., 2000: 491.

Paracaudina ransonnetii .— Heding, 1933: 455.— Djakonov et al., 1958: 377.

Paracaudina chilensis var. ransonnetii H. L. Clark, 1935: 281 .— H. L. Clark, 1938: 540–541.—H. L. Clark, 1946: 444.—A. M. Clark and Rowe, 1971: 194–195, fig. 96a. (synonymy by Liao and Pawson 1992)

Material examined. Western Australia, Roebuck Bay, Broome, Sep 1929, from H. L. Clark collection, AM J6435 (1); Eighty Mile Beach, 19°20'00''S 121°21'00''E, Annabim Expedition 1999, mudflat , WAM Z5637 (1); WAM Z5638 (2); WAM Z5639 (1); WAM Z5640 (1); WAM Z5641 (1); WAM Z5642 (1); WAM Z5653 (1); WAM Z5654 (1); WAM Z5655 (2 tails) . New South Wales, Twofold Bay, Nullica Bay, 9.1 m, 22 Feb 1985 AM J19908 (one 3 mm fragment) . New Zealand, South Island, Tasman Bay, 41.17°S 173.17°E, 0 m, 24 Jan 1972 , NIWA 70956 (2).

Diagnosis. Paracaudina species up to 150 mm total length, diameter up to 20 mm, caudal taper and long discrete tail 80 mm long; posterior body with discrete long thin tail, up to more than half the length of the body; body firm thin leathery to parchment-like, finely wrinkled, variably transversely creased (preserved), live colour off-white with slight purple colouration (H. L. Clark 1938; Liao and A. M. Clark 1995), preserved colour pale grey to pink-grey; mid-body ossicles predominantly octagonal plates with large central perforation bridged by basal box with 4 supporting arms on one side and cross with 4 supporting arms on the upper side, surface knobbed, margin with 8 bluntly pointed projections, plates up to 56 µm across.

Type locality. Chile .

Distribution. Circum-Pacific, including northwest Australia and New Zealand; to 1000 m (Pawson 1963).

Remarks. Ludwig 1883, Théel 1886, Heding 1931, 1933, and Djakonov et al. 1958 judged the Chinese / Japanese species Paracaudina ransonnetii (Marenzeller, 1881) to be a discrete species. Type locality is Yantai (Cheefoo) on the Yellow Sea. H. L. Clark 1935, 1938, 1946 (based on northern Australia material) and A. M. Clark and Rowe 1971 considered the species to be a variety of Paracaudina chilensis (Müller, 1850) . H. L. Clark 1908, Hozawa 1928, Ohshima 1929, Pawson and Liao 1992, Rowe and Gates 1995, and Liao and Clark A. M. 1995 considered Paracaudina ransonnetii to be a junior synonym of Paracaudina chilensis . We agree with this synonymy. We judge that some north-western Australian material is Paracaudina chilensis, and that some north-eastern Australia material (from the Gulf of Carpentaria and Moreton Bay) is a new species Paracaudina keablei O’Loughlin and Barmos that we describe below.

Below we raise the New Zealand species Paracaudina coriacea (Hutton, 1872) out of synonymy with the Chilean species Paracaudina chilensis (Müller, 1850) . Théel 1886 was prompted to refer New Zealand specimens to Caudina ransonnetii Marenzeller, 1881 but finally referred them to Caudina coriacea (Hutton, 1872) . But the ossicles illustrated by Théel 1886 are the predominant ossicle form found in Paracaudina chilensis . We examined two small New Zealand specimens (NIWA 70956) from the shallows of Tasman Bay and found the ossicles to be those of Paracaudina chilensis (fig. 8). We dismissed our consideration that this ossicle form might be a juvenile developmental stage of Paracaudina coriacea on the grounds that Hozawa 1928 found no such significant development changes in his study of Paracaudina chilensis at Asamushi. Both Paracaudina chilensis (Müller) and Paracaudina coriacea (Hutton) occur in New Zealand waters. We note that the distal tail of the specimen of Paracaudina chilensis WAM Z 5638 is not very thin (fig. 1c), while the distal tails of the two specimens of Paracaudina coriacea NIWA 70955 and AM J12290 are both very thin (figs 1d, e).

We also note that some, but not the predominant, ossicles from specimens judged to be Paracaudina chilensis from northwest Australia are similar to the ossicles illustrated for the single type specimen of Paracaudina delicata Pawson and Liao, 1992 taken in the Gulf of Tonkin. And some, but not the predominant, ossicles are similar to those in the new species Paracaudina keablei O’Loughlin and Barmos (below).