PART II. 



SYSTEMATIC SYNOPSIS, 



CLASS BRYOZOA, Ehrenberg, 1831. 1 



Diagnosis. Coelomate Metazoa, the individual members of which 

 are small in size. The body is surrounded by an ectocyst and 

 endocyst, the former of which secretes a cuticle. There is a single 

 nerve ganglion. The digestive canal is ciliated and bent into 

 a U shape, the mouth and anus being situated close together. The 

 mouth is within a circular or horseshoe-shaped ridge, bearing 

 ciliated tentacles (the lophophore). The anus opens either within 

 or outside the lophophore. The larva is free-swimming. 



The Bryozoa are usually fixed, and compound. The individual 

 animals or JBryozoites grow by gemmation into zoaria. 



1 In the discussion as to which of the terms, Polyzoa or Bryozoa, is to be taken 

 as the name of the class, it is assumed that Thompson's name predates Ehren- 

 berg's. Thompson's work is usually quoted (e.g. by Engler) as 1831-4, 

 whereas Memoir No. 5, containing that on Polyzoa, is assigned to 1830 by Busk 

 (Ann. Mag. Nat. Hist. ser. 2, t. x. p. 352) and Hincks (Brit. Mar. Polyz. 

 p. 589). The confusion is probably due to the statement in Mag. Nat. Hist. 

 vol. vii. p. 656, December 1834, that Memoir No. 5 had been "just published" ; 

 but this was a mistake for Memoir No. 6, as the subject is mentioned in the 

 reference. Thompson's series dates from 1828-34 ; the memoir on the Polyzoa 

 was issued in December, 1830, as a long review of it was given in the number of 

 Ferussac's Butt. Sci. Nat. for January 1831. The dates of publication of the 

 various parts are as follows : 

 Memoir 1. ... 1828. Fide Ferussac, Butt. Sci. Nat. t. xvi. 1829, p. 473. 



,, 2. Apr. 1829. ,, ,, t. xx. 1830, p. 312. 



,, 3. Jan. 1830. ,, t. xxii. 1830, p. 331. 



