midline

Immediately behind the hump is a series of knuckles or crenulations along the midline.

The single blowhole is located well to the left of the midline and far forward on the head.

Third vertebral scute: Length of anterior margin, 33; greatest width, 42; length at midline, 40 (estimated).

The pectoro-abdominal suture is anteriorly convex at the sides and concave at the midline.

Nuchal: Width of anterior margin, 12 (estimated); greatest width, 37 (estimated); length at midline, 35 (estimated).