484 Transactions.— Geology. 
water-worn character of the gold, and were it not that the conglomerates 
above mentioned are of Paleozoic age I should consider that it exists in the 
said conglomerates as an alluvial gold. 
Art. LXXVI.— On the Belemnites found in New Zealand. 
By Dr. Hecror, C.M.G., F.R.S., Director of the Geological Survey. 
Plates XXIL, XXIII. 
[Read before the Wellington Philosophical Society, 19th January, 1878.] 
Norwirustanpine that our knowledge of the true nature and function in the 
animal economy of the singular fossils comprised in the group Belemnitide 
is very imperfect, their importance as indicating particular zones in the 
life-development of successive epochs has been fully recognized. That they 
were the internal supports of soft-bodied molluscs allied to the Sepia of the 
present day is certain, but there is no organ strictly analogous to them to 
be found in the structure of any living form of cephalopod. We are there- 
fore ignorant of the extent to which the variations in form in the fossil 
belemnites were dependent on or correlated with important modifications in 
the structure of the complete animal. Nevertheless these varieties are very 
constant and characteristic of the particular geological formations in which 
they are found, so that they afford most valuable indications to the strati- 
graphist. 
The Belemnitide first appear in the liassic period, and survive to the 
close of the eretaceous period. They are divided into two genera—Belem- 
` mitella, which is confined to the chalk or upper eretaceous formations, and 
Belemnites, which, with the exception of a single species (in England at 
least), is confined to the formations below the chalk. 
No representative of Belemnitella, which is distinguished by a ventral 
fissure of the guard and external vascular impressions, has yet been dis- 
covered in New Zealand, so that in the following notes attention is confined 
to the genus Belemnites. 
In order to facilitate the comparison of our belemnites with those des- 
cribed from other countries I reproduce the grouping of the species adopted 
by Phillips, Mayer, and other writers on the subject, modifying it to 
comprise the New Zealand forms. 
1, Acer1.—Club-shaped and laterally compressed, without dorsal or 
ventral grooves, but with lateral furrows. (Liassic. ) 
2. Gastrocatt.—Cylindrical with a distinct ventral groove. (Jurassie.) 
