ball: mollusca and brachiopoda. 373 



keel and the flattening of the straight dorsal slope the appearance of a large 

 escutcheon is produced ; anterior slope arcuate, passing insensibly into the curve 

 of the rounded anterior end ; from the beaks a narrow depressed ray extends to 

 the anterior end of the base, slightly arcuating the sculpture which passes over 

 it, and the basal margin where it intersects : sculpture of concentric, numerous 

 rounded small ridges separated by subequal grooves ; this sculpture covers the 

 whole exterior pretty evenly, except a narrow space near the two radial keels, 

 where it is obsolete ; interior chalky white, muscular scars small, distinct ; pallial 

 sinus small, shallow, pointed beliind ; margins entire ; resiliary pit deep, directly 

 under the beaks, separating twenty-six anterior and about twenty posterior 

 crowded angular hinge-teeth. Lou. of shell, 15.5 ; of beaks behind the anterior 

 end, 7.0 ; alt. 10.5 ; diam. 7.0 mm. 



U. S. S. " Albatross," station 3396, Gulf of Panama, in 259 fathoms, mud, bot- 

 tom temperature 47°.-i F. U. S. N. Mus. 122,910. Also at Tome, Chile, m 14 

 fathoms. 



This species resembles L. dissimilis Sowerby, but has the beaks more anterior 

 and a somewhat differently sculptured rostrum. L. caelata (Hinds, non Conrad, 

 = Z. taphria Dall) is more swollen, shorter, and more polished. 



Leda (Jupiteria) agapea Dall, n. sp. 



Plate 6, figures 4, 5. 



Shell large, thin, fragile, pale straw color, inequilateral, finely evenly, concen- 

 trically wrinkled ; the wrinkles rounded, with subequal interspaces; beaks small, 

 pointed, incurved, closely adjacent, over a chiefly internal, black, amphidetic lig- 

 ament ; lunule smooth, extremely narrow, lanceolate, depressed ; escutcheon not 

 defined, posterior dorsal area extending from tlie beaks to the end of the rostrum, 

 lanceolate, nearly as wide as the shell, bounded by a rounded ridge on each side, 

 which begins as a strong rounded fold near the beaks but gradually weakens ; 

 area inside of it depressed, sculptured like the rest of the shell, enclosing a second 

 similar, but mucli smaller, lanceolate depression beginning close to the beaks and 

 bounded by an indistinctly defined slight elevation of the floor of the main de- 

 pression; outside the latter is a feebly depressed ray extending from the beaks to 

 a slight insinuation of the basal margin, above and behind which the posterior end 

 of the shell ends in a point or rostrum ; anterior end of the shell evenly rounded, 

 base evenly arcuate ; interior opaque white, the margin entire, the hinge with 

 about sixteen teetii on each side of a strong, triangular, black, backwardly iu- 

 clined resilium. Lon. of shell, 21 ; of beaks behind anterior end, 9 ; alt. 12 ; 

 diam. 8 mm. 



U. S. S. " Albatross," station 3360, Gulf of Panama, in 1672 fathoms, sand, 

 bottom temperature 42° F. U. S. N. Mus. 122.911. Also at station 3399, ia 

 1573 fathoms, green ooze, bottom temperature 36° F., ofi" the coast of Ecuador. 



This species is most nearly related to L. pontonia Dall, but has the beaks more 

 anterior and the sculpture coarser and more deeply incised. 



