. Bulletin - United States National Museum. Science. vol. 2, pt. 2.] A TAXONOMIC STUDY OF THE SALPIDAE METCALF. 31 of the eye in C. pinnata (fig. 15, this page). This recalls the condition of the developing eye of C. pinnata during the early part of its rota- tion (fig. 12, D, p. 25). The position of the eye and the undivided condition of its posterior portion, also the less developed state of the plug in the adult Cyclosalpa affinis, parallel features of the immature eye of C. pinnata. Shall we interpret this as indicating that C. affinis is more archaic than 0. pinnata, or as showing it alre
. Bulletin - United States National Museum. Science. vol. 2, pt. 2.] A TAXONOMIC STUDY OF THE SALPIDAE METCALF. 31 of the eye in C. pinnata (fig. 15, this page). This recalls the condition of the developing eye of C. pinnata during the early part of its rota- tion (fig. 12, D, p. 25). The position of the eye and the undivided condition of its posterior portion, also the less developed state of the plug in the adult Cyclosalpa affinis, parallel features of the immature eye of C. pinnata. Shall we interpret this as indicating that C. affinis is more archaic than 0. pinnata, or as showing it already to have begun those retrogressive changes which culminate in the decided degeneration of the eye in the more modified species of Sal- pidae? The approach in the condition of the intestine to that of the true Salpae, a secondary feature, makes one inclined to interpret the divergence in the eye as secondary, a slight degeneration, consisting of an inhibition of some of the later phases of the development. On the other hand, the more regular character of the muscles in the aggregated Cyclosalpa affinis is doubtless more archaic than the condi- tion in C. The evi- dence from the muscles and that from the gut are there- fore opposed. Our studies have inclined us to give weight to the latter and to in- terpret the comparative anat- omy of the eyes accordingly. The two pairs of smaller eyes in the ganglion of the aggregated Cyclosalpa affinis are similar to those in the chain form of C. pinnata. Our figures and description of Cyclosalpa affinis are based upon the study of two specimens of the solitary form, one from an unnamed locality, the other from the Atlantic Ocean, off the mouth of Dela- ware Bay, in latitude 38° 24' north and longitude 71° 17' west [U. S. Bureau of Fisheries station 2717]; of three embryos 11 mm. and 14 mm. long, from the Atlantic Ocean, south of the eastern end of Long Island, in latitude 39° 42' north and longitude 71° 17' west [U. S. Burea
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