"Diagrammatic cross-section of Cray-fish in the thoracic region, to show relation of circulation and respiration. a, appendage; c, carapace; c.f., flap of carapace overhanging the gills; d, digestive tube; g, gill; h, heart; l, liver; m, body muscles; m', muscles of the appendages; n.c., nerve cord; p.s., paricardial sinus; r, reproductive glands; st, sternal artery; v.a., ventral artery; v.s., ventral blood sinus in which the nerve cord lies." — Galloway

Cray-fish

"Diagrammatic cross-section of Cray-fish in the thoracic region, to show relation of circulation and…