CILIOGRADA CIRRIGRADA. 681 



THIRD ORDER. CILIOGRADA. (Lat. cilia, eye-lashes, or vibratile 

 hairs ; gradior, to advance,) or CTENOPHORA, (Gr. XT:EI$, kieis, 

 a comh ; (pogeut, to bear.) 



This order is named from its flat phosphorescent vibrillse or 

 rows of cilia, arranged lengthwise upon the surface of the body, 

 and by means of which it is propelled through the water. It is 

 supposed by some that the cilia are organs of breathing as well 

 as of locomotion. The genus Beroe varies in form from globular 

 to cylindrical ; the cilia also vary in length and position. The 

 species B. ovata, (Lat. egg-shaped,) exhibits the greatest celerity 

 in the movement of its delicate organs, and the most beautiful 

 variety of colors, (see Chart,) as these organs play to and fro in 

 the rays of the sun. The oval-shaped body is open at the large 

 end, transparent, and of a firm gelatinous consistence; easily 

 contracting and widening, but always open and expanded when 

 in motion. The species Beroe, (Cydippe,) pihus, (Lat. a cap or 

 hat,) has a regular body divided into eight sections by rows of 

 cilia. From an internal cavity issue a pair of long retractile 

 appendages, (see Chart,) furnished with vibratory cilia. These 

 beautiful forms are said not often to exceed three inches and a 

 half in length, and two inches and a half in the transverse 

 diameter. Callianyra triploptera, (Gr. triple-winged,) seems in 

 its structure and general character, not far removed from Beroe. 

 It has two pair of winged-shaped appendages, fringed with a 

 double row of filaments upon the edges. (Plate XVIII. fig. 12.) 



The GIRDLE OF VENUS, Cesium Veneris, has a ribbon -shaped 

 body, (see Chart,) sometimes six or eight feet long, its breadth 

 not being as many inches. The margins are fringed with beau 

 tifully colored phosphorescent cilia, which at night gives it the 

 appearance of a band of flame in motion along the water. Some 

 naturalists add a 



FOURTH ORDER. CIRRIGRADA. (Lat. cirri, locks or tufts ; gra 

 dior, to advance.) 



In this order the form is discoidal, and there is an internal dis- 

 coidal skeleton distinguishing these animals from the Pulmoni- 

 grades. They are named from the cirri which are attached to 

 the disk upon which the organs are arranged. Some of the cirri 

 are tubular and furnished with suckers. The Velella, (Lamarck,) 

 in addition to the oval, sub-cartilaginous skeleton, is surmounted 

 by a vertical and oblique crest. This form is widely diffused. 

 The animals are met with far out at sea, often in considerable 

 masses. Sailors are said to fry and eat them. 



