calyculus

It differs from all other American forms, so far described, in the peculiar development of the calyculus.

It is generally distinguished by the scant calyculus and the beautiful richness of its clear delicate net.

The well-defined calyculus is narrowed below and eroded or denticulate above.

The obconic calyculus is always represented in the outline if not in definite structure.

The colors are obscure, but the striations on the calyculus are violet-tinted, and the reds perhaps predominate elsewhere.