vine: classifications of cyclostomatous polyzoa. 349 
In his last work/'' Mr. Busk, in arranging the Cyclostomata, ot 
the Challenger dredgings followed that, which he had previously 
adopted in his Monograph of the Crag Polyzoa, 1857, and in the 
British Museum Catalogue, Pt. III., 1875, "the number of species 
procured by H.M.S. Challenger, belonging to this sub-order, not 
having been sufficiently large to lead to any material change in it." 
In dealing with the Geological distribution of the sub-order, Mr. 
Busk does me the honour of quoting and accepting my opinions on 
two very important points. " To the sub-order Cyclostomata, belong 
most of the oldest Fossil Polyzoa that have been found up to this 
time, whilst ' as yet we have no clear evidence that Cheilostomatous 
types existed in Palaeozoic times : ' (Vine, Quart. Jour. Geol. Soc. 
Vol. xL, p. 332.) Although in the Mesozoic and Tertiary strata Fossil 
Cheilostomata are numerous. The palseontological evidence as to 
the antiquity of the Cyclostomata is fully confirmed and strengthened 
by the embryological researches that have recently been so carefully 
and accurately made by various authors : for instance, M. Barrois 
(Ann Mag. Nat. Hist., ser. 15. Vol. x., p. 391, footnote) says that 
the study of the structure of the larva, and of the formation of the 
cell coincides with palaeontology in furnishing us with perfectly 
concordant results, which are conclusive as to the antiquity of the 
Cyclostomata. "t 
In his latest Paleeontological paper, Mr. A. W. WatersJ remarks, 
suggestively, as follows : — " I would propose that we should divide 
the Cyclostomata into two sub-divisions, namely — first, the Par-.d- 
lelata ; and secondly, the Recbaigulata. This would simplify the 
arrangement of the larger groups, and so far we gain by Mr. Waters' 
suggestion. The lesser gTOups, however, are left nominally the same, 
as arranged by Busk and Smitt, and by the Rev. Thomas Hincks. 
To a large extent, Mr. Waters has been engaged in the study of 
species and groups of Cyclostomata, found in the Upper Tertiary 
Rocks of Australia, as well as the more recent forms. The evidence 
afforded by the study of these is necessarily limited, but in every 
* Report on the Polj zoa (Challenger Rep.), Second Part Cyclostomata, 1883, p, ii. 
f Ibid, pp. iii. and iv. 
X Quart. Journ. Geol, Soc. Aug, 1887. Vol. 42 p. 337. 
