SIMPLICIA. 381 
folded over, completely envelope it. Its cylindrical portion is flanked 
with four projecting ribs terminating in a point and marked by five 
lines of cilia(1). 
The Ocyrozs, Rang., have a similar body with four ranges of 
cilia, but without ribs, and similar wings each furnished at base 
with two ciliated points(2). 
It is also near the Beroes that we musteplace the 
Crstum, 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. veneris, Lesueur, Nouv. Bullet. des Sc., June 1813, pl. vy, 
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(3). 
The two following genera, which were formerly joined 
with the Meduse might also constitute a small family in this 
order, on account of the internal cartilage which supports 
the gelatinous substance of the body. | 
Porpita, Lam. 
Where this cartilage is circular and its surface marked with con- 
centric striz crossed by radiating strie. The superior surface is 
(1) Alcinoé vermiculata, Rang., Mem. de la Soc. d’Hist. Nat. de Par., IV, xix, 
1, 2 
(2) Ocyroé maculata, Id. Ib., xx, 1, 2;—Oc. fusca, Ib. 3;—Oc. erystallina, tb., 4. 
The Callianira heteroptera, Chamiss. and Eisenh., Ac. Nat. Cur., X, p. H, pl. 
xxxi, f. 3, will probably form another subgenus. 
(3) The Lemnisque, Quoy and Gaym., Zool. de Freycin., pl. 86, f. 1, is perhaps 
a fragment of a Cestum. 
