"A sewer, a drain. Rome was intersected by numerous sewers, some of which were of an immense size: the…
This diagram shows a sagittal section of a Rotifer. b, brain; bl., excretory bladder; c, cloaca, the…
"Young skate. The yolk-sac has been cut off, the yolk-stalk is left. m., Mouth; ol.o., nostril, e.g.…
"Diagram of simple type of sponge. c, cloaca; ch, chambers, lined with flagellate entoderm; e.p., external…