vine: classifications of cyclostomatous polyzoa. 347 
Bryozoa,* who accepted the divisions, but not the synoptical 
arrangement of Busk. Professor Smitt, however, based his modified 
arrangement of the Cyclostomata, on apparently more solid ground 
than that of Mr. Busk, but many of his generic divisons were 
suggestive, rather than natural. Mr. Busk says : " Although 
unprepared to follow Professor Smitt in many of his conclusions, 
and disposed to disagree with him in many points as regards the 
limitation of genera and species, the Author is fully convinced that 
Professor Smitt's observations will mark the commencement of a new 
era in the study of the Polyzoa, and that they will serve, in many 
cases, to indicate the direction in which our attempts at their natural 
classification should proceed."! 
In his introductory chapter,^: Mr. Hincks says, respecting Pro- 
fessor Smitt's labours, that " he has aimed at a geneological 
classification, starting with the proposition that the variations of 
species follow^ the line of their development, and may be in a great 
measure explained by it. The Polyzoa .... as compound animals 
offer gTeat facilities for the study of the laws, and causes of variation. 
The differentiation of the colony gives us a series of variations, 
running from the early and simple states, to the fully developed 
form, which is the parallel of the series of differences amongst 
species." As an example of Smitt's meaning, Mr. Hincks cites an 
appropriate example.|| " Thus, the British species of Crissia represents 
the evolutional stages of one and the same type, of which Smitt 
regards 0. fjeniculati, Milne-Edwards, as the first and simplest." 
There is no doubt, whatever, but that Professor Smitt's classification 
of Recent Polyzoa rests on a thoroughness of research, as suggested 
by Mr. Hincks, " and the important contribution which he has made 
towards a natural system," it is impossible to estimate too highly, 
" however much we may be disposed to dissent from some of his 
results."§ Mr. Hincks further remarks, — 1 " In his gTeat work on 
the Embryology of the Polyzoa, Barrois contends that in classifying 
* British Fort. Ofver Scand. Hafs. Bryoz. 1864-5. 
t Catalg. Cyclostomatous Polyzoa (Busk), 1875, p. 1. 
% British Marine Polyzoa, p. cxx., 1880. || Ibid. 
§ Brit. Mar. Polyzoa, p. cxxiii. 1 Ibid. 
