Conularina triangulata (Raymond, Reference Raymond1905), the genotype of Conularina Sinclair, Reference Sinclair1942, is a rare, early Late Ordovician conulariid (Cnidaria, Scyphozoa; Van Iten et al., Reference Van Iten, Leme, Simões, Marques and Collins2006) having three sides or faces instead of four (Sinclair, Reference Sinclair1942, fig. 9; Van Iten, Reference Van Iten1992, text-fig. 3E). Originally described from the Valcour Formation (early Sandbian; Dix et al., Reference Dix, Nehza and Okon2013) on Valcour Island, New York (Sinclair, Reference Sinclair1942), C. triangulata has since been found in laterally equivalent strata of the upper Laval Formation (‘Upper Chazy’; Sinclair, Reference Sinclair1942) in Laval, Québec, Canada (Sinclair, Reference Sinclair1942). From this same unit and area, Sinclair (Reference Sinclair1942) erected three new, four-sided species of Conularina (C. irrasa, C. raymondi, and C. undosa), and he erected a single four-sided species (C. narrawayi) from the Ottawa Formation (now the Sandbian–Katian Ottawa Group; Dix et al., Reference Dix, Nehza and Okon2013) at Tétreauville (now Gatineau), Québec. Subsequently, Jerre (Reference Jerre1994) reported the occurrence of two species of Conularina in the Upper Ordovician of Sweden. Jerre (Reference Jerre1994) also proposed that Eoconularia? forensis Sinclair, Reference Sinclair1946 from the Upper Ordovician Citadelle Formation (‘Quebec City’ Formation; Sinclair, Reference Sinclair1946) in Québec City, Québec (Promontoire de Québec thrust sheet, Appalachian Humber Zone, Allochtonous Domain; Castonguay et al., Reference Castonguay, Tremblay and Lavoie2002) is a species of Conularina.

Unfortunately, the holotype specimen of C. triangulata, collected at ‘Cystid Point’ (Sinclair, Reference Sinclair1942) on Valcour Island and reposited in the paleontological collections of the Carnegie Museum, Pittsburgh (CM 2099), has been lost (A. Kollar, personal communication, 2019). The specimen, illustrated by Raymond (Reference Raymond1908, pl. 54, fig. 18) and Sinclair (Reference Sinclair1942, pl. 1, fig. 8), measured approximately 32 mm long and was truncated a short distance above the (former) apex. Also illustrated by Sinclair (Reference Sinclair1942, pl. 1, figs. 4–7, 9) is a smaller incomplete specimen of this species from the upper Laval Formation in Laval, Québec. This specimen, originally labeled as a hypotype, is housed in the National Collection of Invertebrate and Plant Type Fossils of the Geological Survey of Canada, Ottawa, under collection number GSC 17716. This specimen (Fig. 1) is herein designated as the neotype of C. triangulata, replacing the lost holotype. A second partial specimen, illustrated by Sinclair (Reference Sinclair1942, pl. 1, fig. 10) and numbered GSC 17717, is designated as a paraneotype. This specimen, an internal cast with corresponding external mold, is from the same rock unit and locality as the neotype. Curiously, the neotype now measures approximately 18 mm long, or about 7 mm shorter than shown in Sinclair's (Reference Sinclair1942) figures. Comparison with figures 6 and 7 in plate 1 of Sinclair (Reference Sinclair1942) indicates that the missing portion originally formed the apical-most part of the specimen. We suspect that at one time GSC 17716 consisted of two parts glued together along a fracture and that the smaller (apical-most) part has been lost.

Figure 1. Conularina triangulata (Raymond, Reference Raymond1905) from the upper Laval Formation, Upper Ordovician (Sandbian), Laval, Québec, Canada. View of one of the three faces of GSC 17716, the neotype (specimen oriented with its apertural end at the top of the figure). Scale bar = 10 mm.