4. Stratus lenticularis (Plate [47]). Fall cloud.

Formed by the collapse of cumulus or strato-cumulus. A cloud of evening, easily recognized as lenticular patches. S. L.

5. Strato-cumulus (Plates [38] and [39]).

A term applied to either a stratus which has thickened every here and there into cumulus, or a number of cumulus which have joined together so as to show a nearly continuous common base. S. Cu.

Group Cumulus.

1. Cumulus minor (Plate [43]). Small cumulus.

Cumulus clouds so small as to present the appearance of rounded lumps, no definite pyramidal form or flattened base. Cu. Mi.

2. Cumulus major (Plates [44] and [45]). Large cumulus.

Characterized by a flattened base and rounded clear-cut upper surfaces. Cu. Ma.