what did the description of the whale not say or forgot to say

Chapter Sixty-Eight: The Blanket:

The visible surface of the Sperm Whale is not the least among the many marvels he presents. Almost invariably it is all over obliquely crossed and re-crossed with numberless straight marks in thick array. The whale is wrapped in his blubber as in a real blanket or counterpane, or like an Indian poncho slipped over his head and skirting his extremity. Ishmael compares the construction of the whale to the construction of the dome of St. Peter's cathedral.

Analysis:

The central point of this chapter is the idea that the whale's skin serves as a blanket; Melville therefore constructs the idea that the whale's skin serves as a mask and protection for the whale, hiding some inherent part of the whale. This returns to a dominant theme of the novel, the inscrutability and inability to essentially define the whale. While Melville through Ishmael can describe every detail of the whale and exalt the whale, even comparing it to St. Peter's Basilica, Melville cannot definitively grasp the implications of the whale. This allows the whale in general and specifically Moby Dick to defy any easy interpretation.