368 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



witli a strong black resilium. Alt. 10-15 ; Ion. of shell, 14-21 ; beaks in front of 

 the posterior end, 4-5.5 ; diam. 5-8 mm. 



U. S. S. " Albatross," station 3354, 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 N. tanneri 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 tanneri. 



The specimen figured is not fully mature, but except in size hardly differs fi-om 

 the larger adults. Their respective measurements foUow the diagnosis above. 



Nuciila panamina Dall, n. sp. 



Plate 6, figure 11. 



Shell large, thick, solid, with a dark, polished olivaceous periostracum, smooth 

 surface, and rather douaciform 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 ; Ion. 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. 



lu 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 Dall, n. sp. 



Plate 7, figures 3, 6. 



Shell elongate, almost rostrate, thin, polished, dark olive color, paler on the 

 umboues, subtruncate behind, produced and rounded in front, somewhat com- 

 pressed; beaks small, pointed, sliglitly opisthogyrate, nearer the posterior end; 

 lunuIc and escutcheon not defined, an obscurely defined depressed lanceolate area 

 on the shorter side of the bc;iks with the dorsal margins compressed, descending, 

 arcuate, Icrmiuating at a Ijlunt subtruncate extremity beneath which the basal 

 margin is slightly coucavely arcuate ; the anterior dorsal slope higher, longer, 

 urcuatc, descending to an evenly rounded extremity, the curve passing insensibly 



