R. O. Carnithers — A Reimion of some Carboniferous Corals. 65 



Localities. 

 Visean: Ashfell Beds (S). Thorlieshope and other quarries in the 



Cement Stone Series of Liddelsdale.^ 

 Toumaisian : Z-^ subzone and horizon /3 ; Avon Gorge, Walton Castle 

 (Clevedon), Abbotsleigh, and Burrington (especially at Goat- 

 church Cave). 



Remarlcs. 



The enlarged figures on PI. x of de Koninck's "NouvellesRecherches" 

 of a coral doubtfully ascribed by the Belgian author to Z. Cliffordana, 

 M.-Ed. & H., represents a young example of Z. delanouei. Such was 

 apparent on an inspection of the fi.gured specimen ; two similar ones 

 are represented in the Piret Collection. These, on slicing, afforded 

 sections identical with those cut near the tip of a typical example of 

 the species. 



Diagram C. — Zaphrentis delanouei, M.-Ed. & H. Cement Stones, Licklelsdale. 

 M. 289/. Geol. Surv. Scot. Vertical section in a plane at right 

 angles to the cardinal fossula, showing the tabulae ; the shaded parts 

 represent intersections of septa in the plane of section. X 2. 



Z. delanouei is a well-marked species. Though often identical with 

 Z. omaliusi in size, shape, and epithecal characters, marked differences 

 of septal arrangement are displayed in the calyx and in transverse 

 sections. The curvature of the septa convex, instead of concave, to the 

 cardinal fossula, the large size, the extent, and position relative to 

 the curvature of the corallum, of the cardinal fossula, and the entire 

 absence, at any period of growth, of a counter fossula, are all characters 

 which at once distinguish Z. delanouei from Z. omaliusi. When any 

 doubt occurs, a section in the lower part of the coral should dispose of 

 the difiiculty, since it is here that the septal grouping in these two 

 species is most characteristically shown. 



The only other Tournaisian coral with which, so far as I am aware, 

 the species could be confused, is perhaps Caninia cornucopice, Mich. 

 M. de Koninck noticed that there is a resemblance in the calyx of 

 these two corals. The differences (which are very apparent in 

 transverse sections) will be dealt with in the description of the latter 

 species. 



Certain Yisean Zaphrentids show considerable resemblance to 

 Z. delanouei, though, as will be noticed later, the species itself does not 

 seem to occur in that division of the Carboniferous Limestone, or at any 

 rate, only in the lower part. Of these, a mutation, as yet undescribed, 

 though extremely abundant in the Carboniferous Limestone Series 

 of Scotland, only differs in the constricted shape of the fossula, which 



' Eanging probably from the Upper Tournaisian to the Lower Visean, 



DECABE V. VOL. V. — NO. II. 5 



