NAT. HIST. DIV. VOL. I.
to the margin. It is impossible to express the liveliness of the motions of those delicate organs, or the beautiful variety of colours that rise from them while they play to and fro in the rays of the sun ; nor is it more easy to express the speed and regularity with which the motions succeed each other from the one end of the rays to the other." Dr. Browne frequently met with these animals to the north of the western islands (West Indies).
/3. Species whose cilia are twice as long as the interstices. (Genus, Medea, Eschscholtz.) Example, Berk rufeseens.
7. Species whose cilia are situated in two ambulacral ridges. (Genus, Pandora, Eschscholtz.) Example, Berk Flemingii.
2. Cydippe.
Body regular, freo, gelatinous, divided into eight sections, more or less distinct, by as many double longitudinal rows of vibratory cilia. An internal cavity, with a large buccal (?) aperture, whence issue, and are prolonged more or less below, a pair of long appendages, which are retractile, and also furnished with vibratory cilia.
Example, Cydippe pileus ; Medusa pileus, Gmelin ; Berk pilots, Lamarck ; Plearobrachia, Fleming; Eueharis, Peron, who really established the genus ; but Eschscholtz having transferred the last name to a genus of Ciliobranchians, De Blainville prefers following him, to avoid greater confusion. [BEnifes.] 3. Callianira. [Catxtemna.] 4. Mnemia.
Body smooth, oval, elongated vertically, very much compressed on one side, and as if lobated on the other. Buccal opening between the prolongation of the sides ; conical appendages, on which the rows of vibratory cilia are ranged.
Example, Mnemia heteroptera, Callianyra heteroptera of Chamisso, thus described by Chamisso and Eisenhardt :—Body hyaline, cylin drico-tubu]ar, dilated at one extremity, with a transverse mouth, into which it was impossible to penetrate. A large cestoid wing on each side, with vibratory cilia on its edges; six intermediate smaller wings, of which the four inferior (buccal) are lauceolated, ciliated on the edges, and attached to the base of the body ; two superior cestoid wings uniting themselves to the two large lateral ones, which Peron, according to the describers, erroneously regarded as branchiw.
Calymma. [CALvatme.] 6. Asiotime.
Body a little elevated, a little compressed, or subcireular, prolonged to the right and left into a sort of appendages, bearing the Berko of cilia towards their terminal half only, and up to their end. Mouth small, entirely deprived of labial appendages.
Example, A.riotima Geuha, Eschscholtz. Locality, South Seas, near the equator.
Eucharis (Eschscholtz).
Body ova], sufficiently elevated, slightly compressed, or subeircular, covered with papillae, with the ambulacra of natatory cilia extended from the summit to the base. Mouth small, provided with two rather long pairs of appendages.
Example, Eeeharis Tiedmanni, Eschscholtz. Locality, seas , of Japan. This name had been employed, as we have seen, by Peron, to distinguish another genus of Ciliograda, and should not have been transferred : for in all such cases confusion must be the consequence. The student must now remember that the Eueharis of Peron and that of Eschscholtz represent two different generic forms.
8. Ocyroe.
Body gelatinous, transparent, vertical, cylindrical, provided above with two lateral musculo-tnemhranoua, bifid, thick, wide lobes, and with two fleshy ciliated rib-like elevations, with two other ciliated ribs upon the edges between the lobes : aperture provided with four ciliated arms.
Example, Ocyrde crystalline, Rang, who founded the genus. Do D Itlahwille thinks that it bears much resemblance to the last species of Cafganists—Calliaaira Assragona 1 P. Alcynae.
Body gelatinous, transparent, vertical, cylindrical, with eight ciliated ribs, hidden in part under the vortical natatory lobes. Aper tun! provided with four ciliated appendages.
Example. Akynde mskelzfa, Bang, who established the genus. Locality, coasts of Brazil.