310 GINGLYMACONCHA. VENERIDZ. 
both valves are channelled behind the umbones which extend 
from them to the posterior aspects of the shell. 
The animal with a solitary fistulose tracheal tube fringed at 
its extremity ; the branchize one-lobed and half-jomed toge- 
ther; the foot very much elongated, round and attenuated 
towards its extremity ; the lips are either wanting or very ob- 
solete. 
1. LORIPES LACTEUS. 
Shells thin, sculptured with very narrow striz ; the epider- 
mis pale fuscous. Length and height three-quarters of an 
inch. 
Tellina lactea, Linn. Syst. Naé. 1119. no. 69; Pult. Cat. 
Dorset. 30. t. v. f.9; Mont. Test. Brit. 70: t. mf. 4; 
Poli, Test. i. 47. t. xv. f. 26-29; M. & R. Trans. Linn. 
Soe. vii. 58; Flem. Edinb. Encycl. vu. 92; Wood, Gen. 
Conch. 1. 187; Dill. Dese. Cat. 99; Turt. Conch. Dict. 
176. 
This species is not uncommonly found on the western and 
southern coasts of Devon and Cornwall, generally in very deep 
water. 
Genus 53. Lucina. 
Lucina, Bruguiére, Lamarck, Cuvier. 
Shells nearly round, rather convex ; the hinge in both valves 
bidentate ; the anterior tooth in the left, the posterior tooth in 
the right, notched ; the ligament hinge-shaped and immersed ; 
both valves behind the umbones are very slightly channelled. 
The animal is unknown to me. 
I separated this genus from Te/lina, under the name of 
Egraca, prior to the publication of Lamarck’s last work, and 
before I had seen his ‘‘ Systeme des Animaux sans Vertébres.” 
1. Lucina RapDvULA. 
Shells orbicular, sculptured with concentric lamelle, the in- 
terstices sculptured with elevated concentric striole (narrow 
