AND MONSTROUS FOTiMS OF MEDUSiE. 527 



Cromarty Frith. The size of specimens full of ripe ova was 

 only about two thirds that represented by Forbes ; and instead of 

 having the ovaries, manubrium, and tentacles of an orange- 

 colour, the specimens I observed had these organs of a bluish- 

 white tint. Further, the ovaries did not present the denticulated 

 margins which are to be seen in Forbes's drawings. Lastly, the 

 tentacles are arranged in a double series {i. e. long and short 

 tentacles alternating with one another), and not in a single 

 series as described by Forbes. The number in the large series, 

 however, agrees with Forbes's description. There can thus be 

 no doubt that this is the variety which Ehrenberg met with 

 {vide loc." cit. p. 31 *), more especially as each of the smaller 

 tentacles bears at its base the vesicular body which Ehrenbero' 

 describes as occui-ring in that position. These bodies are re- 

 markable structures, being apparently simple globular cavities 

 without pigments or visible contents of any kind. I do not think, 

 therefore, that they are proper ocelli or eye-specks, as Forbes 

 was very naturally inclined to suppose from Ehrenberg's de- 

 scription of them. Another interesting feature in the histology 

 of this animal is a number of radiating (muscular?) bands, one 

 of which runs to the base of each of the 64 large tentacles. 

 Lastly, the external parts of the ovary are distinctly ciliated, 

 the ciliary action persisting for 20 hours or more after the death 

 of the animal. 



(J) Professor L. Agassiz describes as of very rare occurrence 

 upon the American coast a peculiar variety of Sarsia, presenting 

 six radial tubes, six ocelli, and six tentacles. It therefore be- 

 comes the more interesting to state that I met with a precisely 

 similar variety on the east coast of Scotland. Moreover the 

 occurrence of this variety appears to be as rare in the one locality 

 as in the other ; for of all the many thousands of Sarsia whicli 

 fell within my observation last summer, I only met with one 

 specimen of the variety in question. 



(c) In nearly all the species of naked- and covered-eyed Medusae 

 which I had the opportunity of examining, there was a remarkable 

 absence of monstrous or misshapen forms. In the case of one 

 species, however, such forms were of frequent occurrence. This 

 species was Aurelia awita ; and the monstrosities showed them- 



* It may also be the varietj- of which Hugh Miller speaks : but his descrip- 

 tion is not suificiently precise to admit of dolerrainiiig whicli of the two varieties 



he saw. 



