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.
- photophilous
- photophily
- photophob
- photophobe
- photophobia
- photophobic
- photophobous
- photophone
- photophonic
- photophore
- photophoresis
- photophosphorescent
- photophosphorylation
- photophthalmia
- photophysical
- photophysics
- photopia
- photopic
- photo-piece
- photopigment
- photopile
- photoplate
- photoplay
- photoplethysmograph
- photoplethysmographic