TELLINID, I41t 
behind ; cardinal tooth strong, posterior lateral tooth small ; ligament 
sub-external, marginal, not separated from the cartilage. 
R. perspicua, Hutton, C.MM., p. 65. Ovate, ventricose and 
rounded in front, compressed and sub-angular behind ; umbones pos- 
terior, turned forwards, with broad rounded concentric corrguations that 
show in the interior, and crossed by fine undulating tranverse striz. 
Yellowish-white. 
Height, 2; length, 2°75. 
A single dead specimen from the Bay of Islands is in the Colonial 
Museum, Wellington. 
Genus, CAACELLA—Gray. 
Shell oblong, sub-equilateral. Hinge with the cardinal tooth of left 
valve broad, triangular, notched ; lateral teeth very small, close to the 
cardinal tooth ; cartilage pit produced into the cavity of the shell ; liga- 
ment marginal, near the cartilage. 
C. zelandica, Deshayes, P.Z.S., 1854, p. 335. Shell elongato- 
transverse, elliptic, rather convex, solid, inequilateral, transversely 
striated, covered with a yellowish epidermis, pellucid white, equally 
obtuse and decurrent at each side ; anterior side shorter ; inferior margin 
slightly arched ; cardinal tooth compressed, triangular, accuminate, 
prominent ; pit narrow, deep, oblique, accuminate at the base ; lateral 
teeth narrow, unequal, anterior short; pallial sinus deep, broad, sub- 
trigonal, apex obtuse (Deshayes). 
New Zealand (Cuming). 
Sub-Order—Tellinacea. 
Siphons long, fully separate; mantle wide open in front; outer gill 
lamellar, often rudimental ; foot large. 
FAMILY—TELLINID. 
Palpi large and triangular. Mantle widely open anteriorly and with 
the margins usually fringed or furnished with short filaments, siphons 
very long, slender, diverging ; gills unequal, united beneath. Foot com- 
pressed, broad, geniculate and linguiform. Shell generally with two 
cardinal teeth in each valve, occasionally with lateral teeth; shell com- 
pressed, usually closed and equivalve ; muscular impressions rounded, 
pallial sinus very large ; ligament on the shortest side of the shell, 
external, strong ; cartilage none. 
Genus, PSAMMOBIA—Lamark. 
Oval-oblong, equivalve, sub-equilateral, slightly gaping at each end ; 
hinge straight, teeth %, sometimes bifid, no laterals ; muscular impressions 
large, equally distant from the hinge. 
P. stangeri, Gray, Dief. N.Z,,ii., p. 253; Reeve, Conch. Ic., f. 12. 
Oblong, solid, rounded in front and rather obliquely truncated behind, 
