18 
would ])i*ol)al)ly liavo convinced liim tliat these markings Avcrc not spines. 
In the ‘ Geology ol‘ Canada,’ t he late Mr, Billings figured* an example ot 
Bellerophon avgnslata, Hall, in which the si])lional openings arc even better 
shown than in Professor Hall’s original delineation of Tremanotus, extending 
along- the whole of the middle line of the hack of the last Avhorl. Mr. Miller 
refers Trcmanolus alpheus, Hall, to Bucania Chicagoensis, M‘Chesney ; hut 
although Professor M‘Chesney included his tiguresf of the former under the 
name of the latter, he was careful in his revised paperf to point out that 
they really represented Tremanotus alphens, and the casts of the apertures 
are distinctly visible. Sijihonal ojienings occupying tliis position are not 
alone conlined to Tremanotus in the Belleropliontidm. Por instance, in the 
genus S((tpingosto)n.a, P. Boemer,J 1‘rom the Lower Silurian Boulder Drift of 
East Prussia, a single long slit-like [iperture occurs on the median line of the 
hack in a similar manner to the oval and more numerous one of Tremanotus. 
Lastly, in the genus Tuhlna, Barrande,§ from the Upper Silurian Series of 
Bohemia, the periphery is ornamented with a row of apertures and an 
additional row on each side flanking the median series, all extended into 
curved hollow spines. 
“ Accepting, therefore, the united opinions of Messrs Meek and 
Lindstrdm in favour of retaining Bucania and Tremanotus as separate genera, 
it necessarily follows that the IIaAvkesl)ury fossil has a greater affinity with 
the latter tlian the former. Purthermorc, it must also he admitted that we 
have here a most interesting reap^jearance of a genus suj)posed to have 
closed its existence during the Upper Silurian.” 
This unique shell is quite distinct from either of the Gotland species, 
hut is nearer to T. Hall, or T. angnstata, Hall, as figured by Billings, 
agreeing with the former especially in the broad plait-like ribbing on the 
hack of tlu' outer li]i, and the a])parent absence of much lateral ex])ansion of 
the same. 
Locality . — New Government Docks, Biloela, Sydney. 
Horizon .- — Hawkeshury Sandstone, al: a depth of 25 feet from the 
snrface, in a matrix of limonite. 
CoUector . — J. II. Maiden, Esq., Curator of the Technological Museum, 
after whom the species is named. 
* Oeol. Canada, 18C3, j). .344, f. .3.32. 
t lllustratiniis of New PaLajozoic Fossils, 1SG5, t. 8, f. 4 a-h. 
J Lethaea (4eognostica, Theil 1, Atlas, lS7f>, t. a, 4. 12 a and 3. 
g Owen's Pala.'ontology, ISCO, p. 71, f. 17 (8). 
