The manuscript by Holland and Somorjai is a clear and clean report on the morphological and cellular events occurring during tail regeneration in Asymmetronlucayanum. This is a new species for this kind of studies and the description of the steps in tail regeneration can be compared with what already known in species of the genus Branchiostoma.
I think that the manuscript is of great interest to J. Morphol readers and I support its publication in the journal.
However, I have a general comments concerning the use of the term "somite" in the text. I am well aware that it is widely used in the jargon or people working with lancelets, but the use of the term should be restricted to indicate the blocks of paraxial mesoderm during embryogenesis, whereas, the repeated mass of longitudinal muscles along the adult body should be, more correctly, called myomeres.

Minor comments:
Page 1. The affiliation of IML Somorjai is number 2
Para 3, results, 1st line. The tail is defined as the post-anal part of the body (replace "can be considered" with "is")
Page 7, line 7 from the bottom. The fin box coelom (a cavity) cannot be derived from an epithelium. Probably the authors mean "coelomic epithelium". Please, modify
Page 8, line 15. μm
Page 8, line 21. "undifferentiated-looking"?
Page 9, line 17 and fig. 31. Please, indicate in fig. 31 the degenerating cells.
Page 14, line 5 from the bottom. "...give rise to migrating..."