Home › Volumes › Shells › Univalves and Chitons

Sub-order Tectibranchiata

THIS division embraces families of the Order Opisthobranchiata, in which the shell is seen to disappear by gradual changes, becoming thinner and more enveloped in folds of the mantle and foot as it diminishes in size. The right gill is usually present, but concealed by the mantle fold. The group is not well represented in American waters.