ClipArt ETC
"Sections of types Coelenterates (diagrammatic): 1 (longitudinal) and 2 (transverse) of a tubular hydroid; 3, Sea Anemone (longitudinal); 4, same (transverse, at the level of the upper dotted line); 5, same (transverse section of same at the level of the dotted line. The continuous line is ectoderm, the broken line, entoderm, and the stippled portion, mesenchyma. c.c., circular canal; g, gullet; g.v., gastro-vascular cavity; m, mouth; ma., manubrium; mes., mesentery; mes.1, directive mesentery; o, ostium; r.c., radial canal; t, tentacle; v, velum." -Galloway, 1915

Cnidaria

"Sections of types Coelenterates (diagrammatic): 1 (longitudinal) and 2 (transverse) of a tubular hydroid;…

"B, ciliated planula formed by the continuance of this process. A split in the entoderm furnishes the beginning of the gastro-vascular cavity (g) of the adult." -Galloway, 1915

Hydroid Planula

"B, ciliated planula formed by the continuance of this process. A split in the entoderm furnishes the…