188 



CONTRIBUTIONS TO CANADIAN PALAEONTOLOGY. 



is made up of small slightly convex plates arching upward and inward 

 so as to form an axial vesiculo- tabulate mass whose surface appears in 

 the calyx as a rounded protuberance. Surrounding the central area is a 

 broad vesicular zone in which can be detected the gradual growth upward 

 of the corallum by the superposition of vesicular layers, 2 or 3 mm. in 

 thickness, each layer terminating above in a thin covering of flexuous, 

 continuous lamina; representing the position of the surface of previous 

 calyces. The convex plates composing the vesicular layers are small, 

 generallay 1 mm. or less in length. The septa, starting at the confines 

 of the central vesicular area, radiate outward as their vertical lamina? and 

 disappear in the pripheral region ; they are represented on the calicular 

 surface by the gradually broadening superficial convex ribs, that are 

 connected with each other laterally. In tangential sections at the 

 margin of the calicular expansions the cut edges of the septal ribs, here 

 about 3 mm. in breadth, appear as horizontal continuous parallel wavy 

 lines. What appear to be septal carinas or possibly structures analogous 

 to the supporting processes of the septal laminae as developed in some 

 species of the genus are seen in the radial section of the corallum." 

 (Lambe, 1899.) 



Locality. — Anse a la Vieille, Baie des Chaleurs, one specimen collected 

 by Sir W. E. Logan in 1843 ; Silurian. 



Chonophyllum magnificum. Billing3. 



Chonophi/llum Magnificum, Billings. 1860. Canadian Journal, new series, vol. V., p. 



264, pi. I. 

 n u Rominger. . 1876. Geol. Sur. Mich., Foss. Corals, p. 115, pi. 



XLIIL, upper row. 

 n t. Sherzer. 1892. A revision and monograph of the genus 



Chonophyllum; Bull. Geol. Soc. Amer., vol. 3, p. 267, pi. 8, 



figs. 2, 3, 4 and 5, 



Corallum short and broadly expanding, or cyiindro-turbinate, with 

 gradations between these extreme forms, obtusely pointed and slightly 

 curved at the base, terminating above in a widely spreading calyx whose 

 centre is deeply excavated so as to form a pit, from about one third to 

 nearly one-half the entire diameter in width, from which the septa 

 radiate outward to the periphery ; the type specimen is between 16 to 17 

 cent, broad, about 8 cent, high, and has one hundred and thirty-two septa 

 in the marginal area, other specimens in the collection are of smaller size, 

 a specimen of the cyiindro-turbinate form has a maximum height of 16 

 cent, with a breidth of about 10-5 cent. Septa lamellar on the sides of 

 the pit, bifurcating when about half way up and gradually changing on 

 the expanded margin into low, convex ridges, from about 3 to 5 mm. 

 broad, in the type specimen, near the periphery where they are seen in 



