PANAMIC-PACIFIC PELECYPODA 393 



This is the largest of the Panamic Eurytellinas, recognized by its 

 elongated valves, solid texture, and nearly smooth surface. Often common. 



Range — Nicaragua southward to northern Peru, Panama: Bucaro. 

 Panama Canal Zone: Balboa. Colombia: Isla del Gallo; Choco (Oscar 

 Haught). Ecuador: Sua; San Francisco (Galeras Peninsula); Limones. Peru: 

 Tumbez; Mancora. 



Eurytellina (Eurj'tenma) hertleini, new species Plate 68, figure 6; 



Plate 71, figures 2, 2a 



Tellina laceridens Hanley, 1846, Thes. Conch., vol. 1, Tellina, pi. 61, fig. 176. (Not fig. 



168). Not laceridens Hanley, 1844. 

 Tellina {Eurytellina) planulata Sowerbv, Hertlein and Strong, 1949, Zoologica, vol. 34, 



pt. 2, pp. 76, 77, pi. 1, fig. 22. Not T. planulata Sovverby, 1867. 



Shell ovate-trigonal, white, moderately solid, beaks submedian, the 

 posterior side narrowed, its dorsal margin straight, sloping downward to 

 a narrowly truncated end. The valves are slightly flexed towards the right, 

 hence, the left valve is a little convex while the right is broadly depressed 

 across the posterior-middle zone. The sculpture is formed by narrow, rela- 

 tively strong, flat, concentric ribbons which cover the surface uniformly 

 except on the posterior-dorsal or rostral area where they assume the char- 

 acteristics of irregular growth lines. Interior of a porcellaneous white color, 

 the muscle scars rather deeply impressed. There is no lunule but a slight 

 flattening of the middle zone of the rostral area may correspond to a poorly 

 defined escutcheon. 



Length 54.8 mm., height 33.3 mm., diameter 12.7 mm. Isla del Gallo, 

 Colombia. Holotype, ANSP 218941. 



This apears to be the shell illustrated by Hanley (as fig. 176) and 

 noted in the description of laceridens as a variety of that species. It is also 

 the shell identified as E. planulata Sowerby by Hertlein and Strong. Sower- 

 by's planulata was described without knowledge of locality and is probably 

 not a Panamic species. 



Range — El Salvador to northern Peru. El Salvador and Costa Rica: 

 see Hertlein and Strong for records. Panama: Burica Peninsula; Bucaro. 

 Colombia: Tumaco; Isla del Gallo. Ecuador: Manta; Jaramijo; Palmar; 

 Santa Elena. Peru: Tumbez; Zorritos. 



Enrytellina (Eurytellina) laplata (Pilsbry and Olsson) Plate 71, figures 4, 4a 



Tellina (Eurytellina) laplata Pilsbry and Olsson, 1941, Proc. Acad. Nat. Sci. Philadelphia, 

 vol. 93, pp. 67, 68, pi. IS, figs. 1-5. 



Shell of medium or large size, white, subsolid, coarsely sculptured. The 

 anterior side is decidely longer, wide, well rounded at the end, the posterior 

 side with its dorsal margin descending sharply, straight, to a narrowly 

 truncate end. The right valve is more convex than the left, their ventral 

 margins pressed lightly together due to a slight flexing which makes the 

 posterior end turn slightly towards the right. Sculpture consists of strong, 

 flat concentric ridges or narrow ribbons (.75 to 1 mm. wide), fairly uniformly 

 developed over the whole disk. The left valve has a large, wide lunule, 

 and escutcheon which project outwards as if to clasp the opposite valve 

 while in the right valve the corresponding marginal zone is widely excavated 

 or concave. Both the lunule and escutcheon are strongly and characteristic- 



