S94 AXEL A. OLSSON 



ally sculptured by transverse ridges which as on the posterior-dorsal area 

 represent the continuation of alternate ridges of the surface sculpture. 

 Pallial sinus large and ample but not reaching to the anterior adductor scar. 



Length 50.7 mm., height 31.5 mm., diameter 15 mm. Bayovar. 



Length 60 mm., height 37 mm., diameter 12.4 mm. (Left valve, 

 Bayovar). 



Common as a Pliocene fossil in Ecuador. Recent records are entirely 

 Peruvian. 



Range — Northwestern Peru. Peru: Paita; Bayovar. 



Eurytellina (Eurytellina) eburnea (Hanley) Plate 68, figure 2; 



Plate 71, f-gure 3 



Tellina eburnea Hanley, 1844, Proc. Zool. Soc. London, p. 61 "Tumbez". — Hanley, 

 18+6, Thes. Conch., vol. 1, Tellina, p. 241, No. 36, pi. 58, fig. 91.— Sowerby, 

 1867, Conch. Icon., vol. 17, Tellina, pi. 13, fig. 60. 



Tellina {Eurytellina) eburnea Hanley, Hertlein and Strong, 1949, Zoologica, vol. 34, pt. 

 2, pp. 73, 74; 1950, idem, vol. 35, pt. 4, pi. 2, fig. 7. 



Tellina panamanmsis Li, 1930, Bull. G?oI. Soc. China, vol. 9, No. 3. p. 262, pi. 5, fig. 32. 



Tellina {Eurytellina) panamanensis Li, Pilsbry, 1931, Proc. Acad. Nat. Sci. Philadelphia, 

 vol. 83, p. 436, pi. 41, figs. 4, 5, 6 (good figures). — Hertlein and Strong, 1949, 

 op. cit., vol. 34, pt. 2, p. 76. — Hertlein and Strong, 1955, Bull. Amer. Mus. Nat. 

 Hist, vol. 107, art. 2, p. 198. 



Tellina liana Hertlein and Strong, 1945, Nautilus, vol. 58, p. 105. 



Shell of medium size, coarse, ovate-elliptical, the anterior side about 

 three-fifths the total length, the surface white, overlain by a thin, buff or 

 ochraceous, deciduous periostracum. The posterior side is short, its dorsal 

 margin descending into an obliquely rounded end. Sculpture formed by coarse, 

 narrow, flat, concentric ribbons (two in a millimeter), nearly uniformly 

 distributed over the disk but crowded together on the rostral slope and 

 lunular area. The valves are hardly flexed, the right valve is a little more 

 convex than the right only. A characteristic feature is the large, expanded 

 lunular area in the left valve; there is no corresponding lunule in the right 

 valve, instead the margin of the valve at this point is concave and excavated. 

 Interior white, porcellaneous, the end of the pallial sinus not reaching to 

 the anterior adductor. 



Length 49.4 mm., height 32.3 mm., diameter 14.6 mm. Venado Beach, 

 Panama Canal Zone. 



This species may be known by its heavy, white-colored shell, coarse, 

 even surface sculpture and in having the dorsal areas in the left valve widely 

 expanded and marked with coarse ridges and wrinkles running parallel to 

 the margin. As a subfossil, the shells of this species are common in dredgings 

 from the Panama Canal at Thatcher's Ferry and elsewhere near the Pacific 

 entrance of the canal and specimens from this source were described by 

 Li, under the name "panamensis" and considered as a Miocene species.^* 



Range — Gulf of California to northern Peru. Panama: Bucaro. Panama 

 Canal Zone: Fort Amador; Thatcher's Ferry. Colombia: Isla del Gallo. 

 Ecuador: Charapota; Jaramijo; Manglaralto; Santa Elena. Peru: Tumbez; 

 Boca Pan. 



i*Typical Miocene fossils have been found at Thatcher's Ferry in the canal dredg- 

 ings, probably derived from barge dumps brought here from the Gatun area in the 

 early days of canal construction. 



