. Echinoderms of Connecticut. Echinodermata. 104 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. by its further growth, and the development of plates and spines, it is able to assume the habits of the Fig. i8. Arbacia punctulata. Oral surface of young urchin shortly after the metamorphosis. (After Brooks.) The cl3^eastroids pass through stages very similar to those of the regular sea-urchins. The sand-dollar, for example, de- velops from a long-armed pluteus, which settles to the sand at the sea bottom and gives rise to the young sand-dollar. This has at first a few relatively long spi
. Echinoderms of Connecticut. Echinodermata. 104 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. by its further growth, and the development of plates and spines, it is able to assume the habits of the Fig. i8. Arbacia punctulata. Oral surface of young urchin shortly after the metamorphosis. (After Brooks.) The cl3^eastroids pass through stages very similar to those of the regular sea-urchins. The sand-dollar, for example, de- velops from a long-armed pluteus, which settles to the sand at the sea bottom and gives rise to the young sand-dollar. This has at first a few relatively long spines and large tube-feet. There is now a nearly complete radial symmetry, the intestinal opening at this stage being near the center of the upper surface, some- what as in the regular urchins. With the further growth of the animal, its bilateral symmetry becomes more marked, and the anus is gradually shifted to its final position near or beneath the edge of the disk. Grave* has been successful in rearing large numbers of the key-hole urchin from the fertilized eggs, and following their transformations to the adult form. The egg of this species * C. Grave. Biol. Bulletin, vol. v, Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Coe, Wesley Roswell, 1869-. Hartford, Printed for the State Geological and Natural History Survey
Size: 1541px × 1622px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublisherhartf, bookyear1912
