33 



ACALEPH-E. 



ACALEPH^E. 



Lesueur ; Chrysaora, Peron ; Rhim&twna, Cuvier ; Cassiopea, Peron 

 Cyunea, P<5ron. 



II. GTMJJOPHTHALMATA (yv/j.v6s, naked). 



1. Vessels branched ( Wilteiadat). 

 Genus. \\'illsia, Forbes. 



2. Vessels simple. Ovaries convoluted, and lining the pedunculated 

 stomach (Oceanidce). 



Genera. Turns, Lesson ; Saphenia, Eschscholtz ; Oceania, Peron. 



3. Vessels simple, eight or more. Ovaries linear, in the course of the 

 vessels on the sub-umbrella (jEqiMreadce). 



Genera. Stomobrachium, Brandt ; Polyxenia, Eschscholtz. 



4. Vessels simple, eight. Ovaries as many as the vessels, small, in 

 the course of the sub-umbrella (Circeadte). 



Genus. Circe, Mertens. 



5. Vessels simple, four. Ovaries four, in the course of the vessels 

 on the sub-umbrella (Geryoniadce). 



Genera. Geryonia, P^ron ; Tima, Eschscholtz ; Gcryonopsis, Forbes ; 

 Thaumantias, Eschscholtz; Slabberia, Forbes. 



6. Vessels simple, four. Ovaries in the substance of the peduncle 



Genera. Sarsia, Lesson ; Bongainvittea, Lesson ; Lizzia, Forbes ; 

 Mooderia, Forbes ; Euphysa, Forbes ; Steenstrupia, Forbes. 



This arrangement applies to the British genera only, the species of 

 which, with figures, are described in Professor Forbes's ' Monograph of 

 the British Naked-Eyed Medusae,' published by the Ray Society. 



The second order of the Acalephte are the CILIOGKADA, of which De 

 Blainville gives the folio whig definition : 



1 ! " 1 v gelatinous, very contractile, free, diversiform, evidently binary 

 or bilateral, sometimes appearing subradiated, provided with a kind 

 of straight ambulacra, formed by the approximation of two series of 

 vibratory cilia. 



Intestinal canal complete, or provided with two orifices, a mouth 

 and a vent. 



The term Ciliograde has been given to these Medusae on account 

 of the minute organs called Vibratile Cilia, with which they are 

 covered. 



Arrangement. 



De Blainville, whose amended arrangement we take, observes that 

 systematists have hitherto agreed to imitate Gmelin more or less on 

 the subject of the place of the (Jiliograda, in the animal series, that ia 

 to say, in making them a genus approximating to the Mediate ; and 

 h instances Lamarck, Cuvier, Latreille, and Oken, as not having 

 expressed any doubts on the subject. 

 Genera. 

 1. Beroe. 

 a. Species whose cilia are smaller than the interstices which separate 



them. (Genus, Beroe of Eschscholtz.) 



Example, Beroe mala. Those found by Browne seldom exceeded 

 three inches and a half in length, or two and a half in the largest 

 transverse diameter. "This beautiful creature," says Browne, 'Jamaica,' 

 p. 384, "is of an oval form, obtusely octangular, hollow, open at the 

 larger extremity, transparent, and of a firm gelatinous consistence ; it 



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). 



0. Species whose cilia are twice as long as the interstices. 

 (Genus, Medea, Eschscholtz.) 



Example, Beroe rufescera. 



y. Species whose cilia are situated in two ambulacra! ridges. 

 (Genus, Pandora, Eschscholtz.) 



Example, Beroe Flemingii. 



2. Cydippe. 



Body regular, free, 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 pileui ; Medusa pile-us, Gmelin ; Beroe pile-as, 

 Lamarck; Pkurobrachia, Fleming; Eucharis, 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. [BEKOE.] 



Bcruc ocata. 



contracts and widens with great facility, but is always open and 



expanded when it swims or moves. The longitudinal radii are 



strongest at the crown or smaller extremity, where they rise from a 



very beautiful oblong star, and diminish gradually from thence to 



the margin : but each of them is furnished with a single series of short, 



il.-li. -iite, slender appendices or limbs (the cilia) that move with great 



celerity either the one way or the other, as the creature pleases to 



its flexions, and in a regular accelerated succession from the top 



MAT. HIST. DIV. VOL. I. 



Jlcrijc (Cydippe) pileiis. 



3. Cattianira. [CALLIANIBA.] 

 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, CaUianyra heteroptera of Chamisso, 

 thus described by Chamisso and Eiseuhardt : Body hyaline, cyliu- 

 drico-tubular, 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 lanceolated, 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 branchiae. 



5. Calymma. [CALTMMA.] 

 6. Axiotima. 



Body a little elevated, a little compressed, or subcircular, prolonged 

 to the right and left into a sort of appendages, bearing tie series of 

 cilia towards their terminal half only, and up to their end. Mouth 

 small, entirely deprived of labial appendages. 



Example, Axiotima Gaidia, Eschscholtz. Locality, South Seas, 

 near the equator. 



7. Eucharis (Eschscholtz). 



Body oval, sufficiently elevated, slightly compressed, or subcircular, 

 covered with papilla;, with the ambulacra of natatory cilia extended 

 from the summit to the base. Mouth small, provided with two rather- 

 long pairs of appendages. 



Example, Euchwii Tiedmanni, Eschscholtz. Locality, seas of 

 Japan. This name had been employed, as we have seen, by Pe"ron, 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 Eucharis of Pdron and that 

 of Eschscholtz represent two different generic forms. 



8. Ocyroe. 



Body gelatinous, transparent, vertical, cylindrical, provided above 

 with two lateral musculo-membranous, 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, Ocyroe cryatattlna, Bang, who founded the genus. De 



D 



