Summer squash, which are in market during the summer months, should be young, tender, and thin skinned. The common varieties are the white round and yellow crook-neck. Some of the winter varieties appear in market as early as the middle of August; among the most common are Marrow, Turban, and Hubbard. Turban and Hubbard are usually drier than Marrow. Marrow and Turban have a thin shell, which may be pared off before cooking. Hubbard Squash has a very hard shell, which must be split in order to separate squash in pieces, and squash then cooked in the shell. In selecting winter squash, see that it is heavy in proportion to its size.