368 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
with a strong black resilium. Alt. 10-15 ; lon. of shell, 14-21; beaks in front of 
the posterior end, 4-5.5; diam. 5-8 mm. 
U.S. 8S. ‘ Albatross,” station 8354, Gulf of Panama, in 322 fathoms, mud, bot- 
tom temperature 46° F. U.S. N. Mus. 122,893; station 4654, 24 miles off 
Aguja Point, Peru, in 1036 fathoms, mud, temperature 37°.3; station 2783, on 
the west coast of Patagonia, in 122 fathoms, mud, temperature 48°; station 2779, 
in the Straits of Magellan, in 77 fathoms, ooze, temperature 47°. Orange 
Harbor, Beagle Channel, Rochebrune. 
This differs from NW. tazneri as mentioned under that species; the most conspic- 
uous character is the smooth, polished, and uniformly colored surface of the sava- 
tieri as compared with the concentric color zones and sculpture of ¢anzert. 
The specimen figured is not fully mature, but except in size hardly differs from 
the larger adults. Their respective measurements follow the diagnosis above. 
Nucula panamina DA tt, n. sp. 
Plate 6, figure 11. 
Shell large, thick, solid, with a dark, polished olivaceous periostracum, smooth 
surface, and rather donaciform outline; lines of growth irregular in strength; 
beaks low, small, opisthocoelous, very posterior; no lunule or escutcheon ; pos- 
terior dorsal slope short, direct, flattish; posterior end narrow, rounded; anterior 
slope long, evenly arcuate, anterior end rounded, the base gently arcuate; interior 
of disk pearly, more or less radiately striate, but the valve-margins smooth and 
entire; muscular scars deep, subequal ; posterior hinge line with ten, anterior with 
about twenty, long slightly folded sharp teeth; chondrophore small, narrow, 
anteriorly directed; alt. 16; lon. 22; diam. 9 mm. 
U.S. S. “ Albatross,” station 3360, Gulf of Panama, in 1672 fathoms, sand, 
bottom temperature 42°F. U.S. N. Mus. 122,894. 
In general form this species exhibits a tendency toward that of the next species, 
but somewhat less divergent from the ordinary type of Nucula. 
Nucula taeniolata Da 1, n. sp. 
Plate 7, figures 3, 5. 
Shell elongate, almost rostrate, thin, polished, dark olive color, paler on the 
umbones, subtruncate behind, produced and rounded in front, somewhat com- 
pressed; beaks small, pointed, slightly opisthogyrate, nearer the posterior end; 
lunule and escutcheon not defined, an obscurely defined depressed lanceolate area 
on the shorter side of the beaks with the dorsal margins compressed, descending, 
arcuate, terminating at a blunt subtruncate extremity beneath which the basal 
margin is slightly concavely arcuate; the anterior dorsal slope higher, longer, 
arcuate, descending to an evenly rounded extremity, the curve passing insensibly 
