32 THE CARBONIFEROUS LIMESTONE OF BURRINGTON COMBE 
Special faunal characters. 
Brachiopods. 
Syringothyris cuspidata still occurs, but dies out at the 
top of the horizon. 
Syringothyris aff. laminosa is recorded from this level, 
and not from any higher point. 
Spiriferina cf. laminosa occurs here, and has not been 
recorded from any other level. 
Athyris cf. expansa is not uncommon. 
Seminula aff. ambigua is associated with the first 
examples of Seminula aff. ficoidea. 
Orthotetes aff. crenistria is abundant in the lower part 
of the horizon, but becomes distinctly less common to- 
wards the top, and is rare in the succeeding beds. 
Productus semireticulatus mut. concinnus, is not un- 
common, but has not been recorded above this horizon. 
Productus 0 enters, and is abundant at the top of the 
horizon. 
Chonetes papilionacea is abundant. 
Corals. 
Cyathophyllum (p becomes abundant in the middle of 
this horizon ; declines in abundance towards the top, and 
has not been recorded from any higher level. 
Caninia cylindrica occurs rarely at the base of the 
horizon. 
The bryozoan ‘ Chaetetes ’ tumidus is highly characteristic 
of this horizon. 
This horizon is well defined as the top of the Syringo- 
thyris Zone, for it clearly exhibits the decline and dis- 
appearance of the characteristic corals and brachiopods 
of the zone. It does not, however, possess the characters 
of a satisfactory horizon of faunal overlap. The separation 
of the Syringothyris and Seminula Zones is apparently 
sharp. Syringothyris, Semireticulate Producti and Za- 
phrentid corals have not been found above this level. 
