Coahuilix cf. parrasense Czaja, Estrada-Rodriguez , Romero-Mendez , Avila-Rodriguez , Meza-Sanchez & Covich, 2017

Czaja, Alexander, Cardoza-Martinez, Gabriel Fernando, Meza-Sanchez, Iris Gabriela, Estrada-Rodriguez, Jose Luis, Saenz-Mata, Jorge, Becerra-Lopez, Jorge Luis, Romero-Mendez, Ulises, Estrada-Arellano, Josue Raymundo, Garza-Martinez, Miguel Angel & Paulin, Jose Antonio Davila, 2019, New genus, two new species and new records of subterranean freshwater snails (Caenogastropoda; Cochliopidae and Lithoglyphidae) from Coahuila and Durango, Northern Mexico, Subterranean Biology 29, pp. 89-102 : 95

Coahuilix cf. parrasense Czaja, Estrada-Rodriguez, Romero-Mendez, Avila-Rodriguez, Meza-Sanchez & Covich, 2017 Figures 19-21

Material.

COAHUILA, Don Martín Basin, Sabinas River, Las Adjuntas (Rancho San Carlos), UJMC 416, 417: 101°11'41"W, 27°53'33"N, 354 m a.s.l., 2 shells. DURANGO, Leon Guzmán District, Nazas River, 1 km E of the Bridge Los Cuates, UJMC 418, 103°42'13"W, 25°27'56"N, 1.158 m a.s.l., 1 shell (Figs 19-21).

Description.

See Czaja et al. 2017a: 230.

Shell measurements.

Shell 1 from Coahuila (UJMC 416): SH 0.39 mm, SW 1.44 mm, AH 0.52 mm, AW 0.36 mm, aperture plane inclination relative to shell axis = 58°. Shell 2 from Coahuila (UJMC 417): SH 0.41 mm, SW 1.43 mm, AH 0.46 mm, AW 0.38 mm, aperture plane inclination relative to shell axis = 63°. Shell from Durango (UJMC 418): SH 0.31 mm, SW 1.21 mm, AH 0.45 mm, AW 0.32 mm, aperture plane inclination relative to shell axis = 64°.

Remarks.

The three empty shells from Coahuila and Durango resembles in all details the shells of C. parrasense , a sub-fossil species described recently from a dried-up stream (arroyo) near the town Molino, Parras de la Fuente, Coahuila by Czaja et al. (2017a) (Figs 22, 23). The only difference is the lack of the tooth-like bulges behind the peristome by the present shells so they can be placed only tentatively to this species. The strong inclination of the apertural plane in relation to the axis which reaches almost 60° (Figs 21, 23), is the main difference to the extant C. landyei Hershler, 1985 from Cuatro Ciénegas. Coahuilix parrasense seems to occur in Sabinas River sympatrically with B. sabinasense sp. n.