Vol. 67.] THE AVONIAN OP BUBRINGTON COMBE. 381 



spike from the floor of the calyx. (Very similar forms are known 

 from C-S of the South -AVes tern Province, the Xorth-Western 

 Province — Arnside, etc., County Dublin, etc.) 



The figured section agrees well with fig. 2 «, pi. xxx of the 

 Rush Paper from C-S 1 (Eush Conglomerate or megastoma beds), 

 and possibly our species is actually an earlier member of the same 

 gens ; the only essential difference consists in the fact that a thin 

 external ring of vesicles is developed in the Rush species, and is 

 absent from our Burrington form. 



The figured specimen was found at y ; its damaged state 

 prevented me from founding a new species. 



(2) BRACHIOPODS. 

 Chonetes. 

 I. The small Chonetes of the Lower Tournaisian: — 



Chonetes cf. buchiana. ") 



Chonetes cf. crassistria. I As interpreted in the 

 Chonetes cf. hardrensis. i Bristol Paper. 

 Chonetes cf. laguessiana. J 



(The degree of approximation denoted by ' cf.' is, in all four 

 cases, one of general aspect only.) 



Chonetes cf. buchiana is figured by Davidson (' Dav.' pi. lv, 

 fig. 12). 



Shell small, convex, non-transverse ; ribs coarse and often forked 

 at the margin. A concentric ornament composed of minute folds, 

 which is still seen in the under layer, but is not usually impressed 

 on the cast. 



The resemblance to Ch. buchiana de Kon. of the Upper Visean 

 (D) consists solely in the similarity of ribbing ; the D species is 

 transverse, with a broad rolled beak. 



It is necessary, therefore, to separate this form from Chonetes 

 buchiana under a new specific name ; I propose Ch. stoddarti, in 

 commemoration of the late W. W. Stoddart, of Bristol, who collected 

 the specimens studied by Davidson. 



Occurrence. — This species appears to be very local in its 

 distribution, for it only occurs abundantly in the Avon and at 

 Burrington. It is only known in K^. 



1 In the Rush Paper (pp. 276-77) the following correlation of the con- 

 tinuous sequence — Rush Slates, Rush Conglomerate or megastoma beds, Carlyan 

 Limestone — was made : — 



Carlyan Limestone ] 



and [C,-S r 



megastoma beds. J 



Rush Slates \ Z z -C 1 . 



j 

 Although this con-elation was called in question (pp. 441-42) in the sub- 

 sequent or Loughshinny Paper, it has now been amply confirmed and the 

 apparent difficulties explained. 



