FAMILY PECTINIDA — PECTEN. 175 
Genus Lima, Brug. Animal with numerous tentacular filaments in many series along the edges of its 
mantle: foot very small, and carrying a byssus; mouth surrounded by a very thick and 
fringed labial appendage. Shell longitudinal, subequivalve, eared, slightly gaping on one side 
between the valves: beaks distant ; internal face inclined outwards. Hinge toothless: pit partly 
exterior, receiving the ligament; muscular impression central and trifid. 
IL. squamosa, Lam. (Conran, Mar. Conch. pl. 3, fig. 2.) Shell oblong, with broad and strong scaly 
ribs: hinge oblique; margin plicate. Color, whitish or yellowish. Length, 1:0 —2+5; width, 
0°8-1°2. Florida. 
L. glacialis, Lam. (Conran, Ib. pl. 3, fig. 1. Px. 11, fig. 208 of these pages.) Shell oval, sub- 
equilateral, with numerous subscabrous strie: margin entire. Color, soiled whitish or dull reddish. 
Length, 2°5; width, 1+5. Florida. 
FAMILY AVICULIDZ, 
ANIMAL with the mantle entirely open except along the back, without tubes or ‘peculiar openings, and 
prolonged sometimes behind: foot moderate, with a byssus. SHE often foliated, generally thin, 
pearly subequivalve. Hinge without teeth, or only showing small rudimentary teeth ; an anterior 
notch for the passage of the byssus. 
Genus Avicuta, Brug. Shell oval, fragile, rather smooth: base transverse, straight ; extremities pro- 
duced. Hinge linear, unidentate between the beaks: area of the ligament marginal, narrow, 
channelled. 
A. atlantica, Lam. (A. hirundo, Say, Ac. Sc. Vol. 2, p. 262.) Shell with numerous undulated 
wrinkles disposed in rays: wings broad, rounded, scarcely oblique; valves unequal. Color, red- 
dish brown. Width, 0-7. Southern Coast. 
