THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY, 



[FOURTH SERIES.] 

 No. 74. FEBRUARY 1874. 



XII. — Descriptions of two neio Genera and Species of Polyzoa 

 from the Devonian Rocks. By 11. Alleyne Nicholson, 

 M.D., D.Sc., M.A., F.R.S.E., Professor of Natm-al History 

 in University College, Toronto. 



In the following communication I propose to describe two 

 new genera of Polyzoa which I have been compelled to found 

 for the reception of two remarkable fossils from the Devonian 

 rocks of Western Ontario. Both of these belong to tlie family 

 of the Fenestellidee j but they differ in an extraordinary 

 manner from all previously recorded genera, and present 

 certain points of structure of a very anomalous nature. 



Genus Cryptopora (Nicholson). 



Polyzoary forming a rigid, infundibuliform, calcareous ex- 

 pansion, springing from a strong solid branching root-stalk o)* 

 rhizome. Exterior of the coencecium forming a continuous 

 non-perforated calcareous layer, internal to which is a second 

 or intermediate layer, tlic two being composed of tlie amal- 

 gamated and coalescent branches (" interstices "). The inter- 

 mediate layer is marked by sliallow and bifurcating longitu- 

 dinal sulci, corresponding with the lines between the branches ; 

 and its surface exhibits reticulating lines which correspond 

 with the bases or proximal ends of the cells beneatli ; but no 

 fenestrules are present. The internal surface of the inter- 

 mediate layer carries the cells, which are flask-sliaped, and 



Ann. & Ma(j. N. II. Ser. 4. Vol xiii. 7 



