Pseudocuneopsis perflora H. Chen, H. - Q. Xiang, Y. - M. He, X. - C. Huang & X. - P. Wu 2025, sp. nov.

Pseudocuneopsis perflora H. Chen, H.-Q. Xiang, Y.-M. He, X.-C Huang & X.-P. Wu sp. nov. Material examined. Holotype: NCUPP 250521, shell length 61.02 mm, shell width 20.11 mm, shell height 36.11 mm (Fig. 6 A), Bahe River, Dazhou City, Sichuan Province, China, 31.0978°N, 107.1856°E, in April 2025. Paratypes: 6 specimens, NCUPP 250522 –27, shell length 44.17–63.19 mm, shell width 14.86–19.91 mm, shell height 25.00– 35.09 mm (Fig. 6 B, C), locality and habitat same as holotype. Diagnosis. Shell medium-sized, flat, thick, solid, yellowish-brown without any color rays; anterior margin rounded, ventral margin nearly straight; dorsal margin slightly curved and truncated behind, with an obtuse angle in the middle of posterior margin; shell surface with a low secondary posterior ridge end in the angle on the posterior margin; umbo sculptured with W-shape ridges. Both left and right valves with one or two pseudocardinal teeth. Nacre white. Description. Shell medium-sized, flat, thick, solid, yellowish-brown without any color rays; anterior margin rounded, ventral margin nearly straight; dorsal margin slightly curved and truncated behind, with an obtuse angle in the middle of posterior margin; shell surface with a low secondary posterior ridge end in the angle on the posterior margin; umbo sculptured with W-shape ridges. ligament long, narrow. Anterior adductor muscle attachment elliptical and deep; posterior adductor muscle attachment round. Left valve with two pseudocardinal teeth, anterior tooth wide, posterior tooth slightly thick, and having two lateral teeth. Right valve with one thick elevated pyramidal pseudocardinal tooth and one lateral tooth. Nacre white, and shiny (Fig. 6). Within the incurrent aperture, there are not obvious papillae arranged in one row, without pigmentation; the excurrent aperture without papillae, smooth, with brown pigmentation. The inner gills are larger than the outer gills. Labial palps are thin and small, with brown pigmentation. Etymology. “per-” means “ Lasting, long-lasting ”, and the root word flora means “luxuriant”. The type locality (Bahe River, Dazhou City) maintains pristine aquatic conditions, and the name conveys a wish for the species’ persistent prosperity. Vernacular name. 永盛伪楔蚌 (yong sheng wei xie bang) (Chinese); Everlasting pseudo-wedge mussel (English). Habitat and distribution. The species lives alongside Tongchuania mingiana gen. et sp. nov. in its river section, where other freshwater mussel species are rarely found (Fig. 1 B). Remarks. The dorsal margin is slightly curved and truncated at the rear, with an obtuse angle in the middle of the posterior margin. The shell surface features a low secondary posterior ridge that ends at the angle on the posterior margin, which helps distinguish this species from others in the same genus. Additionally, the umbo is sculptured with dense W-shaped ridges, a feature not found in other species of the genus.