264 BULLETIN OF THE 
Famity LUCINIDA. 
Genus LUCINA Brucikre. 
Lucina antillarum Reeve. 
Lucina antillarum Reeve, Dall, Bull. M. C. Z., IX. p. 186, 1881. 
Habitat. Charlotte Harbor, Florida, 13 fms.; Sigsbee, off Havana, in 182 
and 450 fms.; Yucatan Strait, 640 fms. 
This species is closely related by some of its varieties to Z. costata Conrad, 
of the Florida coast. 
Lucina sombrerensis, n. s. 
Shell white, stout, nearly equilateral, very globular, small, covered with 
sharp elevated thin concentric lamelle, separated by wider interspaces and 
becoming crowded and less prominent toward the basal margin; beaks promi- 
nent, full but not inflated ; lunule very small, wider than long, situated di- 
rectly under the front of the beaks and bounded by a fine groove; posterior 
flexuosity present but inconspicuous, and not modifying the sculpture, which 
is the same over the whole shell except as above specified; outer surface not 
polished, interior the same; lateral teeth, especially the anterior one, promi- 
nent ; cardinal teeth small, nearer the anterior lateral, two in each valve ; lig- 
ament in a deep groove above the hinge-line, which groove extends nearly to 
the posterior lateral; interior of the margin finely crenulate. Lon, 6.5 ; alt. 
6.5; diam. 6.0 mm. 
Habitat. Off Sombrero in 72 fms., two valves; West Florida, 50 fms., one 
small valve. 
This little shell has been known to me for some years from various parts of 
the Antilles, and as, after most thorough search, I have been able to find noth- 
ing like it described, I am driven to the conclusion that it is still without a 
name. 
Lucina leucocyma, n. s. 
Shell in size, form, and concentric sculpture strongly recalling L. sombre- 
rensis, from which it differs in being shorter and higher, in having the concen- 
tric lamella thicker and closer together, and especially five broad radiating 
sulcations, sharper toward the beak and becoming less marked toward the 
margin, except the anterior one which is strong throughout; these have 
the effect of producing on the surface four broad rounded and gradually 
widening ribs which give the shell an unmistakable character. There is no 
other radiating sculpture; the shell is pure white, the beaks considerably 
enrolled and bent forward with a minute lunule under them; the interior is 
white, with a very finely crenulated margin, with two anterior and one poste- 
