.^21 



GENERAL OBSERVATIONS. 



In the North Sea we saw swarms of Medusce 

 swimming in the sea ; for the first time, (the 22d 

 of August, 1815,) we caught a great number of 

 Medusa capillaris, L. On the 27th, another large 

 Medusa was very frequent, which seemed un- 

 known to us. It was distinguished by the edge of 

 the disk being divided into thirty-two small 

 round incisions, and by the great fluctuation in 

 the form. 



The two continued calms, which we had in the 

 Atlantic Ocean, were very advantageous for catch- 

 ing and observing the Molluscw. On the l6th of 

 October we saw for the first time two kinds of 

 Salpoe; the one was a Salpa maxima^ L. ; the other 

 a singular kind, composed of two hermaphrodites, 

 externally different, in which I was so fortunate to 

 observe the reciprocal propagation. The one, 

 which I shall call Hermaphroditus, has already 

 been described by Forskohl, by the name of Salpa 

 pinnata, and is distinguished by its broad elong- 

 ation, in the front and underpart of the body, 

 which is wanting in the Hermaphrodita. The first 

 has a single tolerably long blue stripe on the back 

 and on each side j but tlie latter, in the same places, 



VOL. III. V 



