CLASS PELECYPODA 
187 
tinged with yellowish brown, and marked with direct brown lines in the 
middle of the valves; epidermis straw color, with radiating wrinkles on 
the posterior slope. Length, 3J4 inches. (Conrad.) 
Type in Phila. Acad. Sci.? Type locality, near Santa Barbara, Cali¬ 
fornia. 
Range. Santa Barbara, California, to Panama. In the Pliocene at 
San Diego and the Pleistocene at Santa Barbara, San Pedro and San 
Diego, California. 
Tagelus affinis C. B. Adams, 1852. 
Panama Shells, p. 300. 
Shell much elongated, compressed cylindric, well-rounded at both 
extremities; ventral edge straight or slightly arcuated; white beneath a 
deep yellowish-brown epidermis; with unequal striae of growth; beaks not 
prominent, a little behind the middle of the shell; umbos compressed 
along the middle; ligament broad, with stout nymphal callosities; teeth 
small, one in the left, and two in the right valve. Length, 2.25; height, 
.08; diameter, 0.55 inches. (C. B. Adams.) 
Type in Amherst College Collection. Type locality, Panama. 
Range. Santa Barbara, California, to Panama. 
Subgenus Mesopleura Conrad. 
Tagelus subteres Conrad, 1837. 
Jour . Acad. Nat. Sci. Phila., 7:233; pi. 17, fig. 10. 
Shell linear-oval, inflated or sub-cylindrical, slightly arcuate; beaks 
central, very obtuse, extremities equally rounded; color pale purple, 
obscurely rayed; epidermis yellowish brown, finely wrinkled; teeth two in 
each valve. Length, 2 1 /^ inches. (Conrad.) 
Type in Phila. Acad. Nat. Sci.? Type locality, Santa Barbara, Cali¬ 
fornia. 
Range. Santa Barbara, California, to Panama. 
Family SOLENID7E. 
Genus SOLEN (L.) Scopoli, 1777. 
Shell very long, sub-cylindrical, straight, margins parallel, ends gap¬ 
ing ; beaks terminal, or sub-central; hinge teeth, one in each valve; liga¬ 
ment long, external; anterior muscular impression elongated; posterior 
oblong; pallial line extending beyond the adductors; sinus short and 
square. (Tryon. S. S. Conch.) 
Type. Solen vagina Linnaeus, 
Distribution. World-wide, except Arctic seas. 
Range in time. Carboniferous to Pleistocene. 
