10 slides

1 - Asterias, starfish, t.s. of ray showing general structure
2 - Young starfish, horizontal sec. 
3 - Asterias, starfish, bipinnaria larva, w.m. 
4 - Echinus, young sea urchin, radial section 
5 - Development of sea urchin, eggs in different stages 
6 - Echinus, sea urchin, pluteus larva 
7 - Holothuria, sea cucumber, t.s. 
8 - Holothuria, w.m. of limy bodies 
9 - Bryozoa, moss animals, colony, sec. 
10 - Lingula, Brachiopode, t.s.