656 'Journal of Comparative Neurology and Psychology. 



2. Of these, six are brain commissures, running from ventral 

 lobe to ventral lobe ; two are (esophageal commissures, running 

 between the oesophageal nerves; five are brain-cesophageal com- 

 missures, running from ventral lobe to ventral lobe and through 

 the oesophageal nerves. 



3. Of the brain commissures, some originate in the fibrous 

 core, some in the cellular sheath of the brain. 



4. Six pairs of neurocord cells and one unpaired neurocord cell 

 are found in the ventral lobes of the brain. 



5. The brain, though complex in the number of commissures 

 and neurocord cells, is probably of a primitive type, related to that 

 of the Turbellaria. 



6. There is probably individual variation in the number of 

 both cornmissures and neurocord cells. 



Wellesley College. 

 Wellesley, Mass. • 



BIBLIOGRAPHY. 



Burger, O. 



1894. Studien zu einer Revision der EntwickJungsgeschichte der Nemertinen. Ber. d. Nat. 



Ges. Freiburg, Bd. 8. 



1895. Die Nemertinen des Golfes von Neapel. Fauna u. Flora des Golfes von Neapel, xxii. 



Monographie. 

 1897-99. Nemertini. Bronn's Klassen u. Ordnungen, Bd. 4, Suppl. 



CoE, w. R. ; 



1895. On the anatomy of a species of Nemertean (Cerebratulus lacteus Verrill) with remarks 

 on certain other species. Trans. Connect. Acad., vol. 9. 



HUBRECHT, A. A. W. 



1887. Report on the Nemertea collected by H. M. S. Challenger during the years 1873-1876. 

 Challenger Report, vol. 19. 

 Lang, A. 



1 88 1. Der Bau von Gunda segmentata u. d. Verwandtschaft der Platyhelminthen mit Ccelen- 



teraten u. Hirudineen, Mhth. aus d. Zool. Station zu Neapel, Bd. iii, Heft 1-2. 

 1884. Polycladen. Fauna u. Flora des Golfes von Neapel, xi. Monographie. 

 Montgomery, T. H. 



1897. Studies on the elements of the central ner\-ous system of the Heteronemertini, Journ. 

 Morph., vol. 13. 

 Thompson, C. B. 



1901. Zygeupolia litoralis, a new Heteronemertean. Prcc. Acad. Nat. Sci., Philadelphia. 



