VINE : NOTES ON FOSSIL POLYZOA. 
385 
calice is covered by a thin calcareous plate having- a reniform opening- 
not unlike, in some respects, the area of some species of Polyzoa. 
This reniform opening- is what Mr. Young calls '• perforated tabulae" 
(Fig. 3a). A large number of fossil species, both in this countrj^ 
and also in America, have perforated tabulae, but whether the other 
features which I am about to point out are present also I cannot say. 
Now that attention has been drawn to the subject, I hope more 
special details will be forthcoming. On the same slide of sections of 
Scotch specimens that give me my best evidence of perforated 
tabulae, I have sections of tubes of various stages of growth in 
which the perforation of the tabulae are shown at different intervals 
(Fig. 4). In the older tube the non-entire tabulae are more numerous 
than in the younger tubes, and in every case where I can get a clear 
view of the area, the thin calcareous crust covers — partiall}^— the 
divisional chambers. It is evident that the animal of Tahulipora 
was very different from the animal of that division of M onticulipora 
which embraces the Calamopora of Phillips. Years ago the peculiar 
structures puzzled me, they puzzle me now ; but I live in hope that 
the dawn is approaching, and that ere long light will break upon us, 
not only sufficiently to show the peculiarity of, but the real nature 
and meaning of these palaeozoic anomalies. 
I have already indicated that there are several fossils which 
were apparently known to Phillips that still await description ; these 
I have thought it well to incorporate with the present paper so that 
I may be able to finish my series of notes on the Monticuliporidae 
and Polyzoa from the North Yorkshir e district. 
1. MONTICULIPOEIDA TUMIDA. Phill., PI. XX. 
Fig. 1, A, Natural size. A\ Normal calice surrounded by wall 
and 18 blunt spines (transparent sec), b\ b^, b^, inter-stitial tubuli 
referred to in text. 
Fig. 2, M. tumida, Phill. — 2*, Corallites of the monticules ; 2^ 
Corallites coming to the surface immediately under the monticules, 
and connected with the axial region ; 2"=, Laminar structure of walls. 
Notice the saw-like character of the base of calices in 2'. 
Fig. 3, Tahulipora Urii, Young, showing (a) perforated tabulae, 
(b) one peculiar tabulae with two openings below the " mouth" ? 
