46 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 134 
new species, in its narrower outline, shorter trail, deeper sulcus, and 
more strongly convex lateral profile. The species is represented by a 
single specimen only, but it is fairly well preserved. 
Family ECHINOCONCHIDAE Stehli, 1954 
KOCHIPRODUCTUS TRANSVERSUS Cooper, new species 
Plate 4A, figures 1-6 
Shells moderately large, wider than long and with moderate depth. 
Sides rounded, anterior margin broadly rounded; anterolateral ex- 
tremities narrowly rounded. Surface marked by discontinuous cos- 
tellae swollen anteriorly to form spine bases. 
Pedicle valve with moderately convex lateral profile; anterior pro- 
file moderately convex but with steep lateral slopes and sulcate median 
region. Umbo greatly swollen, beak strongly incurved. Sulcus orig- 
inating on the umbo near the beak, extending to the anterior margin, 
becoming broader and deeper to the valve middle but becoming still 
broader but shallower anterior to the middle. Flanks bounding sulcus 
narrowly rounded. Cardinal extremities not alate. Anterior margin 
with short, ventrally deflected frill. 
Brachial valve gently concave in lateral view but nearly flat when 
seen from the posterior. Umbo marked by a shallow pit anterior to 
which a low, broad fold rises and extends to the anterior margin. 
Fold steepest and somewhat carinate near the valve middle, flattening 
and broadening anterior to the middle but remaining prominent. 
Shell bounding fold gently concave; posterolateral extremities nearly 
flat. Cardinal process long and slender, curved. 
Measurements in mm. 
Middle Surface 
Length width length Thickness 
FIOLOLY PEt cesindon ae clas oer 36.6 44.5 56.0 16.1 
Paraty per (l253sn) noel. 42.7? 55.4 62.0? ? 
Types.—Holotype, U.S.N.M. 125332; figured paratype, U.S.N.M. 
125331. 
Localities —Ptio, P11; S12, S41, S50, S103; U.O. 2201-1, 2216-1. 
Discussion.—This species is characterized by its medium size for 
the genus, transverse form and broad sulcus becoming obsolete an- 
teriorly. The specimens assigned to this new species appear to be 
adults and not the young of K. porrectus which is more strongly 
ornamented. The adult character appears in the short ventrally de- 
flected rim along the margin of the pedicle valve (pl. 4A, fig. 4). 
