R. G. Carnithers — A Revision of some Carboniferous Corals. 73 



oecui's immediately below 7, and it diminishes in numbers in Q,-^. In 

 the Gower the typical species is not uncommon at Threecliff Bay (the 

 base of Cg), but in Upper C3 it is replaced by the Co mutation (for 

 description see notes on the species previously given). From Arnside 

 (Lakesland) in beds which he correlates with Co-S, of the South- 

 western Province, Professor E. T. Garwood cites Z. cornucopice'^ ; the 

 specimens belong to this mutation, and are apparently not uncommon." 



Professor Garwood has kindly allowed me to examine his material; 

 while most of the specimens clearly belong to the Cg mutation above 

 referred to by Dr. Vaughan, one specimen (Arnside) with minor septa 

 of moderate length, I would refer to Z. koninchi as here defined, 

 as also a further specimen from the Caninia bed at Hazelback. The 

 Arnside specimen, in outline, agreed with Z. koninchi, forma /3, as 

 opposed to the forma a commonly found in the Bristol district, but was 

 otherwise similar to the specimens figured on PI. Y. The shape of 

 the Hazelback example could not be ascertained as it was embedded 

 in the limestone. The section agreed very closely with that on PL Y, 

 Fig. 1. 



Some further specimens collected from Arnside by Dr. Wheelton 

 Hind and forwarded to me by Dr. Yaughan, also yielded a good 

 example of Z. koninchi, forma typica, but the remainder belonged to 

 the Cg mutation. 



Summarising the evidence, therefore, it seems that in the Bristol 

 district Z. koninchi characterises the uppermost Tournaisian beds, 

 while in the Gower it occurs at a somewhat higher level, in the lower 

 Yisean, and in the North of England, at Arnside, probably on a still 

 higher horizon, but at both of these last localities a mutational form 

 becomes predominant, 



EXPLANATION OF PLATES. 



Plate IV. 



The register numbers refer to specimens in the British Museum (Natural History) 

 unless otherwise stated. 



Zaphrentis omaliusi, M.-Ed. & H. 

 Figs. \-\a. — Transverse sections from a typical individual, that in Fig. 1 cut just 



below the calyx floor. Indications of a counter fossula are shown. 

 X 3. Tournaisian (Z2 subzone) : AVoodspring, near Bristol. 



Vaughan Collection. 

 Fig. 2. — Profile of a young example, x f. Tournai. R. 11,658. 

 Fig. 3. — Another transverse section, cut just below the calyx floor. x 3. 



Waulsort. Mus. Eoy. d'Hist. Nat. Brussels. 

 Figs. 4-45. — Serial transverse sections of another example, x 3. The calyx 



agrees well with those figured by MM. Milne-Edwards & Haime and 



de Koninck. Tournai. E. 11,675. (Camera lucida drawings.) 



Var. ambigua, var. nov. 

 Figs. b-ba. — Transverse sections from a typical example. x 3. Upper (?) 



Visean : Horrocksford Quarry, near Clitheroe. 

 Fig. 6. — Transverse section just below the calyx of an unusually large specimen, 



lower sections of which agree with those in Figs. 5-5«. x 3. 



Tournaisian (Z zone) : coast at Eush, co. Dublin. Matley 



Collection. 



1 Geol. Mag., 1907, p, 73. 



