more primary branches that are never triangular in section ; in 

 having much larger oral vesicles ; and never anything corres- 

 ponding to the flattened condition of the ultimate branches 

 figured by Tilesius and mentioned by Haeckel. T-he arrange- 

 ment of the white spots and other color markings is also some- 

 what different. It is distinguished from the second by hav- 

 ing fewer of the large oral vesicles and having these of a 

 smaller size ; by having more slender and graceful oral arms 

 than those figured b;- Keller, with a greater number of primary 

 jbranches ; and by a difference in the coloration. 



It is readily distinguished from G. omata , Haeckel, by 

 its large oral vesicles and from C. . MerLensi , Brandt, G. de- 

 pressa , Haeckel, and G. picte , Vanhoffen, by the number of mar- 



ginal lobes. 



GENEPAL DESCRIPTION. 



Form _qf the Body. 

 To one who has only seen the Gyaneas, Aurelias, and the 

 like, of our northern coast, the shape of this medusa appe-rs 

 very strange. The aboral or exumbrella surface, instead of 

 being convex, as one would expect, is concave when at rest, ex- 

 cept for a slight convexity over the stomach, and except in 

 the region of the thinner marginal part of the umbrella, where 



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