book gill
Zoology
noun
(In aquatic arachnids) any of several pairs of external gills that each contain numerous fine lamellae; also called gill book.
- Now only found in horseshoe crabs, book gills are thought to be ancestral to book lungs..
Origin
Late 19th century.
- tropical cyclone
- tropical depression
- tropical forest
- tropical fruit
- Tropicalia
- tropicalise
- tropical island
- tropicalism
- tropicalismo
- tropicalist
- tropicalista
- tropicality
- tropicalize
- tropically
- tropical medicine
- tropical month
- tropical rain
- tropical rainforest
- tropical sprue
- tropical storm
- tropicamide
- nage-waza
- nagger
- nagging
- naggingly