S THE AMPHIOXUS. 



The Neapolitan type is easily to be distinguished 

 l>y its far inferior size, and through a somewhat 

 clearer colouring ; its form too is far slighter, this 

 being specially due to the weaker development of the 

 sexual organs. A circumstance moreover impressed 

 me, which points to a total dissimilarity in the 

 periods of development. This circumstance is that at 

 Faro, with the exception of the pelagic living larvse, , 

 specimens a trifle smaller than the rest were found 

 among the sexually perfect, whereas I received from 

 Naples, during the spawning time, every variety of 

 size. Among these were some very small, measuring 

 but a fraction of the length of the developed speci- 

 mens, smaller than I had ever seen at Faro. 



This points, at any rate, to a different variety. 

 Possibly a closer investigation will yield specific 

 differences. 



SPECIAL POETION. 



IN the special portion of this treatise, in which my 

 observations are set down in a purely descriptive 

 manner, I intend to avoid so far as possible all remarks 

 of a theoretical character. 



Any theoretical discussion is to be found in the 



