V-shaped segments, the point of the V being directed forward. The segments alternate with the vertebrae, and are called myomeres. Such a segmentation is evident, though less marked, in the body wall muscles of the frog, and in the abdominal musculature of the rabbit and other mammals it is still to be traced.
Text Book of Biology, Part 1: Vertebrata · The Wunder Library — complete classics, free to read, with narration.