PEDIGREE OF MOLLUSCS, 161 
Dibranchia 
Heteropoda 
Prosobranchia 
Pulsnonata Tetrabranchia 
Lipobranchia Cephalopoda 
(Cuttles or Poulps) 
Gymnobranchia 
Pleurobranchia —,——’ 
Opisthobranchia Chitonides 
| 
ee es ee ees’ 
Delocephala 
a 
Pteropoda 
Inclusa | 
——_" 
Sinupalliata 
Scaphopoda | 
Integripalliata W—_——— 
Sclerobrachia Siphoniata Perocephala 
Cochlides 
(Snails) 
Sarcobrachia Asiphonia 
Testicardines Lamellibranchia 
(HAlussels) 
Ecardines een: 
Spirobranchia Otocardia 
(Lamp-eshells) (Molluscs with chamber and ante- 
chamber to the heart) 
Ne NT 
Promollusca (Primeval Molluscs 
Molluscs with simple heart 
(Worms) 
Gastreea 
25 
