Lining this are narrow ribs known as septae, each having a tall tentacular lobe near its origin in the centre.

Lining this are narrow ribs known as septae.

There were narrow ribs, curved thighbones, long claw-like metatarsals.

All species except H. diptera have four narrow longitudinal ribs or wings; diptera only has two, making it the most distinctive of the group.

The upper portion of the whorls is smooth, concave, below the periphery with numerous narrow ribs.

The amateur collector is most likely to come across the cycad foliage, with its characteristic narrow central rib and flat leaflets.

They are ornamented by strong, narrow, protractive axial ribs.

The jaw has 11-16 narrow ribs.

Wings are reduced to narrow ribs that run the whole length of the pitcher cup.

In most cases, a pair of narrow ribs is present in place of the wings, although fully developed fringed wings are sometimes encountered.