OBSERVATIONS ON FISH SCALES. 127 
framework are arranged concentric rings of oval elements, which are hyaline with narrow dense margins 
These oval bodies are actually capable of being detached, or more strictly speaking their surface layers 
are detachable, retaining their original form and appearance. 
Fig. 5. —Anguilla rostrata (Anguillidae). Details of sculpture. Bureau of Fisheries. 
Fig. 6 .—Synaphobranchus pinnalus (Synaphobranchidae). Bureau of Fisheries. 
Fig. 7. —Ichthyophis glutinosus (Caeciliidae). Amphibian scale. British Museum. 
SYNAPHOBRANCHIDAE. 
In Synaphobranchuspinnatus (Gronovius), a deep-sea eel, the scales are shaped much as an Anguilla, 
but not so elongate, and very much smaller, the length about two-thirds of a millimeter. The general 
appearance and detailed structure are shown in the figure. In this scale we get a clue to the evolution 
