Conocyathus compressus Tenison-Woods, 1878b: 302–303 (in part: paralectotype), NSW.
Trematotrochus verconis Dennant, 1904: 5–6 (pl. 1, fig. 4), SA.– Howchin, 1909: 45 (listed).– Wells, 1958: 262 (listed). Squires, 1961: 19 (listed).– Shepherd & Veron, 1982: 176, figs. 4.54b (listed).– Veron, 1986: 607 (listed).– Stranks, 1993: 21 (type designation).– Not Cairns, 1988: 388 (= F. parkeri).– Not Cairns, 1997: 26–27, pls. 3e, 6b, 9f (= F. parkeri).
Trematotrochus alternans Cairns & Parker, 1992: 31–32, figs. 8f–h, 9b,c (SA, Vic, NSW, WA).– Stranks, 1993: page 1 of addendum (type deposition).– Cairns, 1998: 364 (listed).
Foveolocyathus alternans.–Cairns, 1997: 27, pl. 6c (new combination).
New records. TASMANIA: Tangaroa 81-T-1-162, 1, NMV F67803; Tangaroa 81-T-1-194, 1, NMV F67822; 81-T-1-201, 2, USNM 92995. — NEW SOUTH WALES: Thetis 49, 2, AM G11963. — QUEENSLAND: Gillett Cay, Swain Reef, 64–73 m (station VI), 1, AM G15381.
Types. Dennant (1904: 6) described the species based on “the type” (= holotype) and an unspecified number of worn specimens from St. Vincent Gulf and Backstairs Passage. The holotype was stated to measure 6× 3 mm in CD and 7.3 mm in height. Not able to find type material of Trematotrochus verconis Dennant, 1904, Cairns & Parker (1992) established a neotype (SAM H542) from the Verco collection that was collected close to the type locality. From Dennant’s figures, they inferred that Dennant included two species in his description: a species having 40 septa and 4 size classes of septa, which Cairns & Parker considered to be typical T. verconis, and a species with a more elongate corallum and more septa, and only 3 size classes of septa, which they named T. alternans n.sp. But, a year later, Stranks (1993) discovered 17 of the purported types of T. verconis at the NMV (F43270). Ironically, all of these type specimens, including one that corresponds to the exact measurement of the holotype (recently recatalogued as F96127), correspond to the species Cairns & Parker described as T. alternans. According to the ICZN (1999: article 75.8), a neotype must be set aside if the original type material is discovered, so F. verconis is the name that must apply to the species having the more elongate calice and higher number of septa arranged in three size classes (F. alternans sensu Cairns & Parker, 1992). Thus, a new name must be provided for the species referred to as F. verconis by Cairns & Parker (1992), i.e., F. parkeri.
The holotype of F. alternans is deposited at the SAM (H547); paratypes are also deposited at the SAM, NNM, NMV, and USNM. Type Locality: St. Francis Island, South Australia, 27–37 m.