68 
Genus — BILLINGSIA, L. G. de Koninck} 
Corallnm composed of compressed corallites, connected by tlieir walls 
and communicating freely with each other by means of mural pores. The 
calices are small, oval, and furnished with several septal strias. Tabulae 
appear to be wanting. 
I have thought it right to establish this genus on account of certain 
corals which from their form have great resemblance to some species of 
Fcwosites and Alveolites. In fact they grow like these, in rounded or 
dendroid mass with radiating corallites, but differing from the first [_Favosites'] 
in the absence of tabulae and in the arrangement of the mural pores, and 
from the second {^Alveolites'] in the shape of the calices which show no 
trace of septal processes. This same character excludes them from Coenites. 
This genus appears to constitute a link between Aulopora and Syringopora. 
Billingsia alveolaris, L. G. de Koninck. 
PL IT, fig. 4. 
Corallnm a rounded or dendroid mass, corallites very numerous, 
arranged obliquely to the axis in the branching portions and converging 
towards the centre in the rounded or gibbous masses ; in diameter they do 
not exceed one half millimetre. The calices are pretty regular, and from their 
position, oblique to the surface, appear a little angular ; the margins are thin 
and the septal striae are but little apparent ; the oval outline of the corallites 
is only seen when they are examined perpendicular to their axis ; a longitudinal 
section proves that they communicate directly with one another by relatively 
large mural pores arranged at variable distances almost in the same way as 
in several species of Syringopora, with the difference that the corallites of 
Syringopora are not directly connected to one another by their walls. 
FLorizon and Locality. — Three specimens of this species have been 
collected in the Yass Bistrict, on the banks of the Murrumbidgee, in a black 
compact limestone, on the surface of which all the structure appears 
clearly owing to their being silicified and weathered by long exposure to 
atmospheric influences. 
^ [This genus lias been proved to be synonymous with Alveolites, hence the species is now known as 
Alveolites alveolaris, vide R. Etheridge, Junr. , and A. H. Foord, Ann. Mag. Nat. Hist., 1884, XIV, p. 176, 
pi. 6, fig. 1-lc, and R. Etheridge, Junr., Geology and PalEeontology of Queensland, 1892, p. 53, pi. 2, figs. l-3a. — 
W.S.D.] 
