138 contributions to canadian palaeontology. 



Cyathophyllum Pennanti Billings, 



Plate XI., figs. 4, 4a, 46. 



Cyathophyllum Pennanti, Billings, 1862. Palaeoz, Foss., vol. I., p. 107. 



Colonies of cylindrical, flexuous, slightly divergent, upright corallites 

 that increase rapidly by lateral calicular gemmation, forming masses 

 from 30 to 60 cent, in diameter. Three or four buds spring from a parent 

 corallite at a time. Corallites crowded closely together and frequently 

 in contact, annulated by numerous rounded swellings, with shallow con- 

 strictions between; small nodular outgrowths are developed when the coral- 

 lites approach each other sutRciently and serve to strengthen the general 

 growth of the colony. Epitheca marked by numerous faint, transverse 

 lines of growth, and striated longitudinally by narrow septal grooves. 

 The corallites, in some specimens bud at intervals of from 3 to 6 cent, 

 after having attained a diameter of from 10 to 15 mm., but in others, 

 evidently on account of overcrowding, they bud with much less frequency. 



Septa numbering sixty, alternately large and small, one-half passing to 

 the centre, remainder reaching not quite half way. Tabulse well developed, 

 close set, about eight in a space of 2 mm. flat in the centre and shallowly 

 grooved round the periphery, occupying about half the entire diameter. 

 Vesicles small, inclined obliquely outward and upward and filling the 

 interseptal loculi in from about three to six rows. 



This coral is closely allied to C. articulatum, Wahlenberg, from which 

 it difiers in being less strongly annulated and in the possession of the 

 strengthening nodular outgrowths as well as in a few minor details of 

 structure ; the strengthening connexions between the corallites give to 

 the corallum an appearance somewhat similar to that of some species of 

 D iphyphyllum. 



Locality. — L'Anse au Gasgon, Bale des Chaleurs ; Silurian* ; collector 

 Sir William Logan, 1843. 



Cyathophyllum Zenkeri, Billings. 

 Plate XII., fig. 1. 



Cyathophyllum Zenlteri, Billings, 1860. Canadian Jovirnal, new series, vol. V., p. 262, 

 fig. 11. 

 Nicholson, 1875. Palieon. of Ont., p. 76. 



Corallum simple, short, cone-shaped, strongly curved especially at the 

 pointed base, reaching a height of 9 cent, as measured on the convex or 



* See foot-note on page 129. 



