Describe the anatomy of the body wall of an earthworm in short.

(N/A) The body wall of the earthworm consists of the following layers:
$1$. Cuticle: The body is covered externally by a thin,non-cellular layer called the cuticle.
$2$. Epidermis: Below the cuticle lies the epidermis,which is composed of a single layer of columnar epithelial cells,including secretory gland cells.
$3$. Muscle Layers: Beneath the epidermis,there are two layers of muscles: an outer layer of circular muscles and an inner layer of longitudinal muscles.
$4$. Coelomic Epithelium: The innermost layer is the coelomic epithelium,which lines the body cavity.