568 MR. J. A. DOUGLAS ON THE [XoV. 1909, 



The following points are of especial interest in correlating these 

 beds with the Seminula Zone in the South-Western Province of 

 Great Britain : — 



1. In County Clare, Clisiophyllids and Lithostrotion have not been recorded 



from the Syringothyris Zone, but appear for the first time in S r 

 Since, however, Lithostrotion martini, which throughout is the 

 dominant coral, is in some localities absent, or extremely rare, at the 

 base of the subzone, this horizon is defined by the first appearance of 

 the Clisiophyllids. 



2. The survivors of a Tournaisian fauna are not numerous. They include 



Camjwphyttiim cylindricum, which, as in the Bristol sequence, attains 

 its second maximum in S,, Zaphrentis omaliusi var. densa, and 

 Mickelinia grandis. 



3. Syringothyris cuspidata does not extend into these beds. 



4. Daviesiella cf. comoides is abundant in S x (compare the Mendips). 



5. Productus punctatus is not uncommon (compare Weston-super-Mare). 



6. Productus cf. semireticidatus occurs sparingly in S lf and Pr. com is 



abundant throughout S 2 . 



7. The most characteristic feature in S 2 is the horizon of Isematophyllum 



and CarcinophyMum, which I believe is also recognized in the North 

 of England. 



8. Seminula is everywhere rare, except at the summit of S 2 . 



■9. As in the Bristol area, this zone is characterized lithologically by the 

 development of oolitic limestone ; here, however, it sometimes attains 

 the nature of a conglomerate, and is remarkable for its abundant 

 gasteropod-fauna, whereas Seminula is absent or extremely rare in 

 these beds. I have been unable to determine the exact level of these 

 oolitic beds, but they probably occur at or about the base of S,. 



The simultaneous occurrence of Syringopora reticulata and 

 Miclielinia grandis at the base of Sj suggests a correlation with 

 the megastoma beds of the Rush sequence. 



The Dibunophyllum Zone. 

 D x = subzone of Dibunophyllum 6. 



This subzone in County Clare attains a thickness which cannot be 

 less than 1000 feet, and is thus comparable with the sequence in 

 the Midland area. The corals are more or less similar in the two 

 districts, though certain forms, such as CyatJiopliyllum murchisoni, 

 Alveolites, and Carcinopliyllum, which are rare in the Midlands, are 

 here of common occurrence. The brachiopods are more numerous 

 in County Clare, and it is interesting to note that such forms as 

 Dielasma hastatum, Seminula ambigua, Productus elegans, Athyris 

 planosulcata, and Martinia lineata which in the Midlands charac- 

 terize D 2 are here abundant in ~D l ; whereas many of the Midland 

 D 1 forms are in County Clare more commonly associated with 

 Lonsdalia. 



The correlation of these beds with the 1), subzone of the South- 



