Abstract. We prove that the study of the category C-Comod of left comodules over a K-coalgebra C reduces to the study of K-linear representations of a quiver with relations if K is an algebraically closed field, and to the study of K-linear representations of a K-species with relations if K is a perfect field. Given a field K and a quiver Q = (Q 0 , Q 1 ), we show that any subcoalgebra C of the path K-coalgebra K Q containing K Q 0 ⊕ K Q 1 is the path coalgebra K (Q, B) of a profinite bound quiver (Q, B), and the category C-Comod of left C-comodules is equivalent to the category Rep (M, B), up to isomorphism, is also discussed.