This aestivation is imbricate.
Is similar to that in Limulus, whilst the imbricate triangular pieces of the posterior median region resemble the similarlyplaced structures of Limulus in a striking manner.
With very few exceptions, the integuments form imbricate scalelike folds arranged with the greatest regularity; they are small and pluriserial on the upper parts of the body and tail, large and uniserial on the abdomen, and generally biserial on the lower side of the tail.
The integuments of the head are divided into non-imbricate shields or plates, symmetrically arranged, but not corresponding in size or shape with the underlying cranial bones or having any relation to them.
The leaves are small and imbricate, and are borne on flattened branches, which are apt to be mistaken for the leaves.
This variety of imbricate aestivation has been termed cochlear.
47 a section is given of the bud of Antirrhinum majus, showing the imbricate spiral arrangement.
In Convolvulaceae, while the corolla is twisted, and has its parts arranged in a circle, the calyx is imbricate, and exhibits a spiral arrangement.