trigonic (trigonik)

[ Trigoniidæ (trig-o-ni'i-dē), n. pl. [NL., IMG:content-0872.png:[graphic] valves. The mantle margins are free and siphons; the branch iæ are ample and unequal; the foot is long and angulated be hind; the palpi are small and pointed; the shell is equivalve and nacreous within; the umbones are ante median; the ligament is external; the cardinal teeth are diver IMG:content-0873.jpg:[blocks in formation] Structure of Trigoniidæ (Trigon i a pectin at a). gent, and more or le transversely striated; and the pallial impre ion is entire. It is a group of mollusks whose living line; t, t, dental sockets; u, cloaca. species are few and con a, a ', adductors; 1, foot; hl, hinge ligament; It, labial tentacles or palpi;, margin; 0, mouth, pallial fined to the Australian seas, but which had an extensive range from the Tria ic to the Cretaceous epoch. The typical genus is Trigon i a. Also Trigoniadæ, Trigonidæ. See also cut under Trigon i a.