hemal cavity
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circulation — circulable /serr kyeuh leuh beuhl/, adj. /serr kyeuh lay sheuhn/, n. 1. an act or instance of circulating, moving in a circle or circuit, or flowing. 2. the continuous movement of blood through the heart and blood vessels, which is maintained… … Universalium
echinoderm — /i kuy neuh derrm , ek euh neuh /, n. any marine animal of the invertebrate phylum Echinodermata, having a radiating arrangement of parts and a body wall stiffened by calcareous pieces that may protrude as spines and including the starfishes, sea … Universalium
gland — An organized aggregation of cells functioning as a secretory or excretory organ. SYN: glandula (1) [TA]. [L. glans, acorn] accessory g. a small mass of glandular structure, detached from but lying near another and larger g., to which it is… … Medical dictionary
Starfish — For other uses, see Starfish (disambiguation). Asteroidea redirects here. For the Asteraceae subfamily, see Asteroideae. Sea Stars Temporal range: Ordovician–Recent … Wikipedia
reproductive system, animal — Introduction any of the organ systems by which animals reproduce. The role of reproduction is to provide for the continued existence of a species; it is the process by which living organisms duplicate themselves. Animals compete with… … Universalium
skeleton — skeletonless, adj. skeletonlike, adj. /skel i tn/, n. 1. Anat., Zool. the bones of a human or an animal considered as a whole, together forming the framework of the body. 2. any of various structures forming a rigid framework in an invertebrate.… … Universalium
Bryozoa — Temporal range: Upper Cambrian–Recent[1] … Wikipedia
Brittle star — Temporal range: 488.2–0 Ma … Wikipedia
arch — Any structure resembling a bent bow or an a.; an arc. In anatomy, any vaulted or archlike structure. See arcus. SYN: arcus [TA]. [thru O. Fr. fr. L. arcus, bow] abdominothoracic a. a bell shaped line defined by the lower end of the sternum and… … Medical dictionary
Marsh rice rat — Temporal range: Rancholabrean (300,000 years before present) – present Conservation status … Wikipedia
