WORMS, ZOOPHYTES, AND PROTOZOA, 



IN 1843 AND 1844. 



BY 



PROFESSOR C. TH. V. SIEBOLD, 



VEKMES ANNUL ATI. 



THE Annelids have of late frequently become the subject 

 of attention to naturalists. They have not only received 

 additions in many new genera and species, but their internal 

 organization has also been illustrated by numerous observers. 



CH^ETOPODES BRANCHIATI. A very copious Memoir on 

 the intimate structure of the nervous system of the Anne- 

 lida has been furnished by Quatrefages (Ann. d. Sc. Nat. 

 torn, ii, 1844, p. 81), in which Eunice sanguinea, Sav., 

 Nereis Beaucondrayi, Aud. et Edw., Glycera MeckeUi, Aud. 

 et Edw., PhyUodoce pellucida, Quatr., the genus Glycera, 

 Aud. et Edw., and Aricmella, Quatr., have been the princi- 

 pal subjects of investigation. 



The genus Aricinella, instituted by Quatrefages (ib. p. 

 95), is provided, as a head, with a long acuminated ros- 

 tellum, without any appendage, but which supports on its 

 dorsal aspect two distinct eyes. The same active naturalist 

 (Comptes rendus, torn, xix, 1844, p. 195 ; or Froriep's n. 

 Notiz. Nr. 674, p. 215) discovered the auditory organ in a 

 new Amphicora, Ehrenb., consisting of an auditory capsule 

 provided with otolithes, and placed on each side of the fore- 

 most segment of the body. According to the observations 

 of Quatrefages (Comptes rendus, 1844, p. 77 ; or Ann. d. 

 Sc. Nat. t. i, 1844, p. 17), the vascular system in various 



