II. Note on the later stages in the development of Balanoglossus Kowalevskii (Agassiz), and on the affinities of the enteropneusta

Abstract

In the “ Quart. Journ. Micr. Sci.,” vol. xxiv, n.s., p. 208, I described the embryonic stages in the development of a small species of Balano­glossus which is found on the American coast. By a direct embryonic development, this animal reaches the condition in which one pair of gill-slits is present, no “ Tomaria ” stage being passed through.