4. Spumellarian Morphology 1 a) Cortical shell only, usually with pores. b) Medullary and cortical shells and spines. c) Shells and polar spines that are connected by an external circular ring. d) Medullary and a constricted cortical shell with polar caps.
5. Spumellarian Morphology 2 a) discoidal and lenticular forms, with medullary and cortical shells, sometimes with protruding spines. b) spongy shells are common in a number of different forms. c) gated forms occur due to encircling girdles.
6.
7. Nassellarian Morphology 2 a) cephalis only (here with some feet). b) cephalis and thorax only (here with large cephalic horns and abdominal feet). c) cephalis, thorax, and abdomen only (with horn). d) as in c) plus one post-abdominal segment e) as in d) plus three or four post-abdominal segments
8. Other Morphological Features a) perforate plate pores. b) spongy pores. c) rectangular (left) and polygonal or honey-combed (right) pores. d) circular pores. e) cephalic tube. f) peristome around the aperture. g) teeth around the aperture.