MISCELLANEOUS. 255 



angles of the two lobes. — Plate LIV. fig. 5. The lower extremity consists 

 of two circular compartments separated by an interval, fig. 6. Both 

 figures are enlarged. Eight vertical ciliated belts traverse the body. The 

 inner belts on the compressed sides are crossed by twelve ridges, the outer 

 by fourteen, which number is probably dependent on the age or the size 

 of the specimen. 



(B.) Two specimens much larger, may be possibly comprehended un- 

 der the same genus, the one taken in February, the other in August. 



The under extremity did not consist of two separated circular com- 

 partments, as in fig. 6. 



The general conformation of the rest corresponded. Two lobes, far 

 apart, prolonged from the lower ovoidal portion, constituted the higher por- 

 tion ; four ciliated tags, endowed with considerable motion, rose from the 

 angles of the lobes. Eight vertical ciliated belts traversed the lower 

 ovoidal portion. 



This animal extended an inch and a half, fig. 4. 



The other was quite as large. 



These larger animals were transparent ; a central channel throughout 

 was visible, but I cannot determine the position of the mouth. 



The body of all these creatures was quite smooth. Eschscholtz de- 

 scribes his specimens as covered with papillae, and says their native region 

 is the seas of Japan. 



Plate LIV. Fig. 4. Beroe bilobata. 



5. Specimen of the same, or a variety, enlarged. 



6. Under extremity of fig. 5, enlarged. 



§ 4. Beroe pileus — Pleurobranchia pileus. — Plate LI II. Figs. 4, 

 5, 6, 7. — This animal has attracted the notice of a greater number of ob- 

 servers than any other of the Medusan race ; and it seems proportionably 

 distributed throughout the world. 



The body is a sphere deficient of a small segment ; about six lines 

 in diameter, though seldom occurring of that size. 



Thus, it lies still and motionless, Plate LIII. fig 4. When about to 

 move, eight ciliated ribs begin to display their action : the animal rises in 



