THALAMUS
Thal"a*mus, n.; pl. Thalami. Etym: [L. thalamus chamber, Gr.

1. (Anat.)

Defn: A mass of nervous matter on either side of the third ventricle of the brain; — called also optic thalamus.

2. (Bot.) (a) Same as Thallus. (b) The receptacle of a flower; a torus.

THALASSIAN
Tha*las"si*an, n. Etym: [From Gr. (Zoöl.)

Defn: Any sea tortoise.

THALASSIC
Tha*las"sic, a. Etym: [Gr. (Geol.)

Defn: Of or pertaining to the sea; — sometimes applied to rocks formed from sediments deposited upon the sea bottom.

THALASSINIAN
Thal`as*sin"i*an, n. (Zoöl.)

Defn: Any species of Thalaassinidæ, a family of burrowing macrurous
Crustacea, having a long and soft abdomen.