. Ctenophores of the Atlantic coast of North America. Ctenophora; Ctenophora. CTENOPHORES OF THE ATLANTIC COAST OF NORTH AMERICA late in ontogeny and grow outward from the sides of the 8 meridional canals and may anastomose, thus producing a network connecting all 8 of the canals, and forming a complex circum-oral canal-system. This remarkable similarity in respect to their canal-systems, together with their marked compression in the funnel-axis, may, I think, be taken as an indication that the Beroidas and Cestidae are related and derived from a common stock. The condition exhibited by the fu

- Image ID: RDNH5N
. Ctenophores of the Atlantic coast of North America. Ctenophora; Ctenophora. CTENOPHORES OF THE ATLANTIC COAST OF NORTH AMERICA late in ontogeny and grow outward from the sides of the 8 meridional canals and may anastomose, thus producing a network connecting all 8 of the canals, and forming a complex circum-oral canal-system. This remarkable similarity in respect to their canal-systems, together with their marked compression in the funnel-axis, may, I think, be taken as an indication that the Beroidas and Cestidae are related and derived from a common stock. The condition exhibited by the fu
The Book Worm / Alamy Stock Photo
Image ID: RDNH5N
. Ctenophores of the Atlantic coast of North America. Ctenophora; Ctenophora. CTENOPHORES OF THE ATLANTIC COAST OF NORTH AMERICA late in ontogeny and grow outward from the sides of the 8 meridional canals and may anastomose, thus producing a network connecting all 8 of the canals, and forming a complex circum-oral canal-system. This remarkable similarity in respect to their canal-systems, together with their marked compression in the funnel-axis, may, I think, be taken as an indication that the Beroidas and Cestidae are related and derived from a common stock. The condition exhibited by the fusion of the paragastric and meridional systems of canals in the young Beroidae and in mature Cestidae is shown in fig. 3, the lettering being similar in purport to that of fig. 2. •nvSV. •msv Fig. 3.—Diagram showing character of canal system in mature Cestidae and young Beroidae. In the Beroidae the meridional and oral canals finally give off side branches which may anastomose, and form circum- oral connectives, but these branches are not shown in the figure. We may classify the Ctenophorae in six orders as follows: I. Cydippid^g : Body spherical or cylindrical, or widest in the tentacular diameter. Two long tentacles with or without side branches. The tentacles arise from pit-like depressions in the sides of the body, which constitute sheaths into which the tentacles may be withdrawn. The meridional and para- gastric vessels do not fuse, but end blindly. No oral lobes, and no auricles. II. Ganeshid.^: Moser, 1907, Zool. Anzeiger, Bd. 31, p. 788; also, 1908, Revue Suisse de Zool., tome 16, p. 12. Body compressed in the tentacular axis. The oral forks of the 2 paragastric canals form a complete (?) ring-canal around the mouth, and the 8 merid- ional canals join this ring-canal. The interradial and tentacular canals arise directly from the funnel. A tentacle-sheath is present. There are no oral lobes and no auricles. The only known form is Ganesha elegans Moser, from the Ma

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