426 ACALEPHA, 
Ipya, Oken—which are merely in the form of a sac, furnished with 
ciliated ribs and open at both ends* 
Some—Do.ioLum, Otto—are even if destitute of ribs, their form re- 
sembling that of a barrel without a bottom ft. 
The Catuanm®, Pér., only seem to differ from Beroe by having 
much more projecting ribs united in pairs, forming two species of 
wings. Their internal organization is not yet well known. 
The Tanirm, Oken, appear to approximate to Callianira, but they 
are figured, on each side, with three long ciliated ribs, and two long 
ramous filaments § 
The Atcinors, Rang., have a cylindrical body, open at one ex- 
tremity and furnished at the other with two lar ge wings, which, when 
folded over, completely envelope it. Its cylindrical portion is flanked 
with four projecting ribs terminating im a point and marked by five 
lines of cilia |). 
The Ocyrors, Rang., have a similar body, with four ranges of 
cilia, but without ribs, and similar wings, each furnished at base with 
two ciliated points 4 
It is also near the Beroes that we must place the 
Crestum, Lesueur, 
A very long gelatinous riband, one of whose margins is furnished 
with a double row of cilia; they are also apparent on the inferior 
edge, but are smaller and less numerous. It is in the middle of the 
inferior margin that we find the mouth, a wide aperture opening into 
a stomach placed transversely in the ‘thickness of the riband, and 
terminating by a very small anus. From the anal extremity arise 
vessels which traverse both extremities of the riband. Two sacs, 
probably ovaries, open on the sides of the mouth. This animal may 
be compared to a Callianira with two ribs, and excessively elongated 
wings. ‘The only species known is the 
C. venerts, Lesueur, Nouv. Bullet. des Sc., June 1813, pl. v. 
f. 1. Its length, or rather width, exceeds five feet, and it is two 
inches in height. It inhabits the Mediterranean, and is very 
difficult to preserve entire **. 
The two following genera, which were formerly joined with the 
* The Beroé ovatus, Brug., or Medusa infundibulum, Gm.; Brown, Jam., XLIII, 
2, and Encyc., XC, 1;—Beroé macrostomus, Pér., Voy., pl. xxxi, f. 1;—Beroé ovata, 
capensis, punctata and constricta, Chamiss. and Hisenh., Ac. Nat. Gat og ay) Ponds: Bl. 
XXX and Xxxi. 
N.B. The animal of Martens, Spitzb., pl. P. f h, which is considered as identical 
with that of Brown, should rather be approximated to the first subgenus. 
t Doliolum mediterraneum, Otto, Ac. Nat. Cur., XI, p. II, pl. xl, f. 4. 
+ Callianira didiploptera, Pér.: Ann. du Mus., XV, pl. ii, f. 16. 
§ Beroé hexagone, Brug.; Encyc. Vers, pl. 90, f. 6. 
|| Alcinoé vermiculata, Rang., Mem. de la Soc. d’Hist. Nat. de Par., IV. xix 
1, 
{ Ocyroé maculata, Id. Ib., xx, 1, 2;—Oec. fusca, Ib. 3:—Oc. crystallina, Ib., 4. 
The Callianira heteroptera, Chamiss. and Hisenh., Ac. Nat. Cur., X, p. II, pl. 
xxxi, f, 3, will probably form another subgenus. 
** The Lemnisque, Quoy and Gaym., Zool. de Freycin., pl. 86, f. 1, is perhaps a 
fragment of a Cestum. 
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