PANAMIC-PACIFIC PELECYPODA 69 



D. Sculpture lines varied, concentric on the anterior side and more or less 

 oblique on the middle and posterior zones. A smooth ray generally 

 borders the posterior carina. 



7. » „ A. exoptata 



Adrana cultrata Keen Plate 3, figures 1, 2 



iVucula elongata Sowerby, 1832, Proc. Zool. Soc. London, p. 197 (Xipixapi).— Sowerby, 

 1833, Conch. Illust., Nuculae, pi. 14, fig. 2.— Reeve, 1841, Conch. Icon., Laeda 

 vol. 1, p. 110, pi. 84, fig. 2. Not A^. elongata Bosc, 1801, or Defrance, 1825. 



Leda elongata Hanley, in Sowerby, 1860, Thes. Conch., vol. 3, Nuculidae, p. 106, sp. 

 1, pi. 227, fig. 39. 



Adrana elongata (Sowerby), Hertlein and Strong 1940, Zoologica, vol. 25, pt. 4, p. 409, 

 pi. 2. fig. 16.— Hertlein and Strong, 1955, Bull. Amer. Mus. Nat. Hist, vol. 107, 

 art. 2, p. 170. 



Adrana cultrata Keen, 1958, Bull. Amer. Paleont, vol. 38, No. 172, pp. 240, 241. New 

 name for A'^. elongata Sowerby, preoccupied. 



Blade-shaped, highest under the beak which is nearly central, the 

 posterior-ventral margin evenly curved, the anterior-ventral margin slightly 

 sinuated. The shell is rather thin, semitransparent, gaping at both ends, 

 white, under an excessively thin, brown or olivaceous periostracum, the 

 surface sculptured with fine, threadlike striae, so fine above as to appear 

 almost wanting, close and regular in the middle, more remotely spaced in 

 front. Average length, 50 mm. 



Range — Mexico to Ecuador. 



Adrana snprema (Pllsbry and Olsson) Plate 3, figure 5 



Nuculana (Adrana) sufrema Pilsbry and Olsson, 1935, Nautilus, vol. 48, No. 4, p. 117, 



pi. 6, fig. 1. 

 Adrana suprema (Pilsbry and Olsson), Hertlein and Strong, 1940, Zoologica, vol. 25, 



pt. 4, No. 25, p. 411. 



The shell is long, strongly compressed, subequilateral, with dark olive- 

 brown epidermis (largely or wholly lost in specimens seen); glossy. The 

 dorsal outline is nearly straight, the ventral margin gently convex, straight- 

 ened or slightly concave towards the posterior end, the greatest height being 

 about the anterior third of the length. Anterior end more obtuse than the 

 posterior. Dorsal areas extremely narrow, bounded by inconspicuous angles. 

 Sculpture of weak growth lines and excessively fine and clear-cut longitudinal 

 striae, obliquely crossing the lines of growth posteriorly, mainly curving 

 with them in the anterior half. They are wanting in a band along the dorsal 

 side, but extend nearly to the ends. Interior white, the pallial sinus occupy- 

 ing more than one-third of the total length, truncate at the end. Tooth-row 

 long, occupying 60% of the whole length, anterior and posterior series of 

 about equal length, teeth very small V-shaped. Cartilage pit very shallow, 

 about 10 mm., long in the type. Length 107 mm., height 23.5 mm., semi- 

 diameter 4.6 mm. — [Pilsbry and Olsson, 1935]. 



This is the largest Adrana and is distinguished by the nearly central 

 beaks, those of A. cultrata are a little more anterior. 



Range — Panama. Panama: Beach between Port Guanico and the 

 Guanico River, Los Santos Province. 



Adrana sowerbyana (d'Orbigny) Plate 3, figures, 3, 3a 



Nucula lanceolata Lamarck, Sowerby, 1833, Conch. Illust., Nuculae, p. 3, pi. 14, fig. 1. 



