. Bulletin - United States National Museum. Science. 24 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. the ventral thin-walled ends of the rod cells of the arch of the horseshoe. There are no intermediate cells between the rods and the pigment cells in the eyes of the aggregated Cyclosalpa pinnata. Such intermediate cells are present in the eye of the solitary form. In the aggregated zooids of C. pinnata, as in those of all other species whose eyes have. Fig. 10.—Cyclosalpa pinnata, aggregated zooid, a transverse sec- tion THROUGH THE GANGLION AND THE TWO POSTERIOR LIMBS OF THE DORSAL EYE. X 150
. Bulletin - United States National Museum. Science. 24 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. the ventral thin-walled ends of the rod cells of the arch of the horseshoe. There are no intermediate cells between the rods and the pigment cells in the eyes of the aggregated Cyclosalpa pinnata. Such intermediate cells are present in the eye of the solitary form. In the aggregated zooids of C. pinnata, as in those of all other species whose eyes have. Fig. 10.—Cyclosalpa pinnata, aggregated zooid, a transverse sec- tion THROUGH THE GANGLION AND THE TWO POSTERIOR LIMBS OF THE DORSAL EYE. X 150 DIAMETERS. FROM METCALF (1893, C). been studied, the pigment cells are superficial. In the solitary C. pinnata they lie deeper among the cells of the optic ridge. Goppert (1892) has shown the presence of ovoid phaeosphaeres in the rod cells of the large eyes of the aggregated forms of Cyclosalpa pinnata and Pegea confederata, also in the eye of the solitary Salpa e maxima. I have not succeeded in demonstrating these, but doubtless careful work upon better preserved material would show them. One can not doubt the accuracy of Goppert's studies. The development of the large eye of the aggregated Cyclosalpa pinnata must also bc-lu, be described, as it is an im- Fig. 11.—Cyclosalpa pinnata, aggregated form, a portant aid to Understand- TRANSVERSE SECTION OF THE DEVELOPING EYE. THE Jjjg ^q taXOllOmic Value Of the TWO ANTERIOR LIMBS (e) OF THE AT THIS STAGE HORSE- . , , shoe-shaped eye are shown, x 200 diameters, comparative anatomy oi tne from metcalf (1893, c). ey0S 0f the aggregated forms of the several species of Salpidae. When first discernible the rudiment of the eye is exactly similar to that in a young embryo of the solitary Cyclosalpa pinnata, a horseshoe-shaped ridge of cells, above the ganglion, with the ends of the horseshoe anterior (fig. 11). The simplo horseshoe shape of the eye of the solitary. Please note that these images are extracted from scanned page images t
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