15 
GASTEliOPODA. 
Order. — Prosol)i*aiicIiiata. 
Family.— BELLEBOFIION TIB jE. 
Oemis. — TEEMANOTUS, llall, 18G7. 
(20th Animal lloport, Regent’s Univ., New York State Cab. Nat. Hist., 18G7, p. 247.) 
Tremanotus Maideni, Fth.,jnr. 
PI. II, Pigs. 1.5-17. 
2\ Maideni, Etheridge, jun., Ann. Report Dept. Mines, N. S. Wales, for 18SC [1887], p. 174. 
App. N., plate. 
Sp. Char. — Shell discoitlal, strongly trumpet-shaped, thin ; whorls five 
or more, visible on both sides, elliptical in section, the last one snh-angular at 
the sides, but the inner whorls with the flanks much more rounded ; apertural 
expansion much prolonged upwards, hut not greatly expanded laterally ; the 
anterior or outer lip reflected backwards, and the slit, if present, not visilflo 
from imperfection of preservation ; inner lip apparently not much reflected ; 
siphonal openings numerous, close together, oval, and situated on rather 
raised oblong prominences, which give to the periphery a rather brokcn-keelcd 
appearance ; surface of shell ornamented with spiral fluctuating lines, parallel 
to the dorsal keel, and which on the expanded outer lip become coarser and 
more plait-like. Length, 4 in. ; breadth, 2 in. 
Ohs. — T. Maideni Avas described in the last Annual Eeport of the 
Department, Avhen the folloAving remarks Avere made on it : — 
“ The shell in question may belong to cither one of tAVO genera — 
Bucania, Hall, ov. Tremanotus, Hall — precisely as certain points in its struc- 
ture arc interpreted. Both these genera are members of the extinct family 
flellerophontidae, and nearly allied to Bellerophon itself. The family became 
extinct at the close of the Bala3ozoic Period, Avith the exception of one genus, 
Belleropjhina, Avliieh appeared and died out in the Cretaceous Epoch. If the 
present shell is determined to be a Bucania, we have here simply a survival 
from the underlying Carboniferous rocks, at the termination of AAdiich period 
the genus ceased to exist. On the other hand, should the controversial point 
of structure, shortly to be touched upon, be maintained in favour of 
Tremanotus, we cannot help regarding the Ilawkesbury fossil as a very 
interesting reappearance of a pecidiar Upper Silurian typo of Gasteropoda. 
