JSO AXEL A. OLSSON 



Strong, rising into short leaflike lamellae along the posterior-dorsal margin. 

 Pallial sinus deep, almost free from the pallial line below. 



There are two Recent species in the Panamic-Pacific region. 



I. Surface sculpture regular and uniformly developed. 



P. jluctigera 



II. Surface sculpture developed unequally over different parts of the disk. 



P. pristiphora 



Phyllodina flnctlgera (Dall) Plate 68, figure 9; 



Plate 69, figure 5 



Tellina {Phyllodina) fluctigera Dall, 1908, Bull. Mus. Comp, Zool., vol. 43, No. 6, pp. 

 419, 420. 



Shell solid, elongate-ovate, nearly equilateral, of a dull yellowish-white 

 color. Umbones low, flat, the beaks small and inconspicuous. The left valve 

 has a long, subtriangular, flattened lunule over the anterior lateral tooth. 

 Surface sculpture is formed by rather strong, concentric riblets, flattened 

 and shelving over the middle of the disk, more erect and crowded on the 

 sides. The posterior-dorsal or rostral area is defined by an umbonal angle 

 in the left valve across which the sculptural lamellae bend sharply at right 

 angles; at the dorsal margin, the ends of these lamellae become erect 

 to form short, stout, leaflike scales. 



Length 32 mm., height 20 mm., diameter of left valve 4.5 mm. Holo- 

 type Panama Bay (Dall). 



Length 29.2 mm., height 17.1 mm., diameter of left valve 4.4 mm. 

 Zorritos, Peru (G. Petersen dredging). 



A rare species, as yet, known only from a few specimens. The holotype 

 in the United States National Museum was dredged in the Gulf of Panama 

 in 182 fathoms. A left valve was dredged by Dr. G. Petersen off Zorritos, 

 Peru, in about 24 brazas depth. 



A closely similar or identical species occurs as fossil in the Esmeraldas 

 beds of northwestern Ecuador. 



Range — Panama to Peru. Panama: Gulf of Panama (USNM). Peru: 

 Zorritos. 



Phyllodina pristiphora (Dall) Plate 69, figure 11 



Tellina (Phyllodina) pristiphora Dall, 1900, Proc. U.S. Nat. Museum, vol. 23, No. 1210, 

 p. 316, pi. 4, fig. 14.— Pilsbry and Lowe, 1932, Proc. Acad. Nat. Sci. Piilladelphia, 

 vol. 84, p. 132.— Hertlein and Strong, 19+9, Zoologica, vol. 34, pt. 2, pp. 86, 87. 



Shell small or of medium size (length up to 35 mm.), subovate, com- 

 pressed, nearly equilateral, the anterior side rounded, the posterior narrower 

 and squarely truncated at the end. The rostral area is well defined, strongly 

 sculptured, with small but prominent, elevated squarish foliations along its 

 dorsal margin. Surface greenish-white, chalky, sculptured with evenly 

 spaced concentric lamellae which are separated by wider and finely con- 

 centrically striated intervals; on the right valve, the lamellae tend to be- 

 come obsolete on the anterior two-thirds of the disk. 



Length 16.5 mm., height 9.5 mm., diameter 3 mm. (Dall). 



Length 35.8 mm., height 23 mm., diameter both valves 10.2 mm. (an 

 unusually large specimen, Hertlein and Strong). 



This is a shorter and higher species than T. jluctigera Dall and with 

 less regular sculpture. 



Range — Lower California to Costa Rica. 



