OBSERVATIONS ON POLYZOA. 



203 



According to this view of their relations, the PHYLACTO- 

 L^MATA comprise three families, or subgroups. First ; 

 the Fredericellidts, founded upon the great differences be- 

 tween the lophophore and nervous system of Fredericella, 

 and the members of the other families. Second ; the Plu- 

 matellidcE, which differ from the Frederieellidse in the lopho- 

 phore and nervous system, and from the Cristatellidse in 

 their coencecial characters. Third ; the CristatellidcB^ whose 

 coenoecia and mode of development separate them widely 

 from both the preceding. 



The following is a scheme of this classification, enumer- 

 ating the families and genera by name, and the number of 

 species at present known in America, Europe, India and 

 Australia. 



I I * 3 



1114 



FREDERICELLIDJS. 



PLUMATELLID.K. 



CRISTATELLID.K. 



Fredericella. 



Plumatella.* 



Lophopus. 



Pectinatella. 



Cristatella. 



12 16 1 1 30 



*Plumatella includes Alcyonella, which is only a variation of the ordinary form of 

 the species. 



|A species of Plumatella mentioned, but not named or described, from Melbourne, 

 and the vicinity of PJclunond. D. Oyly H. Alpin. Ann. and Mag. Nat. Hist. 3d Ser. 

 Vol. 6, p. 454. 1860. 



JA species mentioned by Dr. Leidy. Proc. Phil. Acad. Nat. Sciences, Vol. 10, p. 190. 



||A statoblast, found near Bombay and described by Mr. J. H. Carter in the Ann. 

 and Mag. of Nat. Hist. Vol. 3, p. 341, pi. 8, f. 8rl5, 1859, supposed by him to belong to 

 Lophopus crvstallinus. It, however, undoubtedly belongs to a new species of Pec- 

 tinatella, and I therefore propose for this new species, which is remarkable for its 

 spines, furnished with many lateral hooks, growing only from the ends of the stato- 

 blast, the name of Pectinatella Oarteri, 



