Elimia christyi ( Lea, 1862 )

Minton, Russell L., Bogan, Arthur E., Brooks, Jeff A. & Hayes, David M., 2004, Taxonomic revision of Elimia christyi and E. interrupta (Mollusca: Caenogastropoda: Pleuroceridae), Zootaxa 735, pp. 1-9 : 3-5

Elimia christyi ( Lea, 1862)

Christy’s Elimia

Goniobasis christyi Lea, 1862

Lea 1862, 269; Lea 1863, 328, pl. 38, fig. 185 Goniobasis instabilis Lea, 1862

Lea 1862, 269; Lea 1863, 329, pl. 38, fig. 186 Goniobasis interrupta ( Haldeman, 1840)

Goodrich 1940, 18; Adams et al. 1990, 24; Dillon 1992, 1 Elimia interrupta ( Haldeman, 1840)

Burch and Tottenham 1980, 148, fig. 428; Burch 1982, 40; Burch 1989, 148; Bogan et al.,

1997, 1; Turgeon et al. 1998, 66

Lithasia christyi ( Lea, 1862)

Bogan et al. 1997, 18

Type Designation and Locality: Lectotype USNM 118451, Valley River, Cherokee County, North Carolina ( Graf 2001). Graf (2001) invalidated Baker’s (1964) selection of ANSP 122447 on the basis of it not being the figured specimen, not being from the type locality, and of dubious origin from collectors.

Etymology: Named for Professor David Christy who collected the specimens Lea used in describing the species ( Lea 1863).

Known Distribution: Dillon (1992) reported E. christyi from the following localities: Hiwassee River, 0.1 km upstream of Murphy, Cherokee County, NC; Shuler Creek, 2 km north of Apalachia Dam, Cherokee County, NC; Valley River, Murphy, Cherokee County, NC; Coker Creek, 12 km north of Pine Ridge, Polk County, TN; Hiwassee River, 4 km north of Pine Ridge, Polk County, TN; Hiwassee River, 11 km north of Benton, Polk County, TN; and Hiwassee River, Reliance, Polk County, TN. Recent collections ( NCSM 6595) have been made in the Hiwassee River upstream of the Apalachia Dam powerhouse.

Diagnosis: Ovately conic shell with numerous lirae on all whorls, with brown bands internally and an oval aperture. Diagnosable from other Elimia in the Tennessee River system by its sculpture, and from Lithasia species by its lack of a posterior callus on the columella. Distribution limited to the Hiwassee River drainage.

Description: Shell thin and ovately conic, height to 20 mm; whorls five to six. Adult body whorl frequently ornamented with six to eight lirae, other whorls with fewer. All whorls are axially plicate, giving the lirae a nodulose appearance as they cross the folds. Aperture one­half shell length or slightly more, oval, with a poorly defined columella. Color greenish­brown to brown, often covered with black oxides, frequently with brown bands internally corresponding to the external lirae. Fine transverse growth lines faintly visible; sutures impressed.

Taenoglossan (2:1:1:1:2) radula with rachidian central tooth wider than high, with nine pointed cusps; central cusp longer the rest. Lateral teeth with seven to nine cusps; central cusp rectangular, three to four times wider than the others; leading edge even. Inner marginal teeth with 16 to 18 rounded cusps, outer marginals with eight to nine rounded cusps ( Fig. 1 F & G).

Figures

FIGURE 1. Shells and radulae from recognized and nominal Elimia species. A. Eight landmarks used for morphometric analyses shown on an illustration of E. interrupta modified from Burch and Tottenham (1980). B. E. interrupta, lectotype, ANSP 8760 a, 13.6 mm x 7.4 mm. C. Goniobasis christyi, lectotype, USNM 18451, 16.5 mm x 9 mm. D. G. instabilis, lectotype, USNM 118976, 13.2 mm x 7.5 mm. D. E. interrupta, NCSM 29499, 13.6 mm x 7.2 mm. E. E. interrupta, NCSM 6595, rachidian and laterals. Scale bar 100 µm. F. E. interrupta, NCSM 6595, marginals. Scale bar 100 µm.