DALL: MOLLUSCA AND BRACHIOPODA. 378 
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 
Tounded small ridges separated by subequal grooves; this sculpture covers the 
whole exterior pretty evenly, except a narrow space near thé two radial keels, 
where it is obsolete ; interior chalky white, muscular scars small, distinct; pallial 
sinus small, shallow, pointed behind; margins entire ; resiliary pit deep, directly 
under the beaks, separating twenty-six anterior and about twenty posterior 
Crowded angular hinge-teeth. Lon. of shell, 15.5; of beaks behind the anterior 
end, 7.0; alt. 10.5; diam. 7.0 mm. 
08, 8, “Albatross,” station 3396, Gulf of Panama, in 259 fathoms, mud, bot. 
tom temperature 472.4 F. U. S. N. Mus. 122,910. Also at Tome, Chile, in 14 
fathoms, 
This species resembles Z. dissimilis Sowerby, but has the beaks more anterior 
and a somewhat differently sculptured rostrum. Z. caelata (Hinds, non Conrad, 
= L. taphria Dall) is more swollen, shorter, and more polished, 
Leda (Jupiteria) agapea Darr, n. 8p. 
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, amphidetio lig- 
ament; lunule smooth, extremely narrow, lanceolate, depressed; escutcheon not 
defined, posterior dorsal area extending from the beaks to the end of the rostrum, 
anceolate, 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 much 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 
4 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, 
àse evenly arcuate; interior opaque white, the margin entire, the hinge with 
about sixteen teeth on each side of a strong, triangular, black, backwardly in- 
clined resilium. Lon. of shell, 21; of beaks behind anterior end, 9; alt. 19; 
diam. 8 mm. 
U. S. 9, « Albatross,” station 3360, Gulf of Panama, in 1672 fathoms, sand, 
bottom temperature 49° F. U. 8, N. Mus. 122,911. Also at station 3398, in 
1573 fathoms, green ooze, bottom temperature 36° F., off the coast of Ecuador. 
ns N " . 
This Species is most nearly related to Z. pontonia Dall, but has the beaks more 
niar $5) 
“erior and the sculpture coarser and more deeply incised. 
