Hzcron.—On the Belemnites found in New Zealand, 489 
Belemnites first appear in the calcareous conglomerate, and constitute 
the whole mass of the belemnite beds, almost to the exclusion of other 
fossil forms, but they continue plentiful up to the black grit, in which they 
become scarce. 
The next bed above the black grit is the boulder sand or saurian bed, 
. and in this no belemnites have been found; but they again appear in the 
concretionary greensands, but are there represented only by the peculiar 
forms which I have shown to result from the exfoliation of the perfect 
guards, and no trace of a belemnite possessing the upper part of its guard 
or phragmacone has been discovered in any bed above the black grit. This 
disappearance of the perfect belemnites in the upper greensand strata may 
be, I think, accounted for by the gradual change in the nature of the matrix, 
and the accession of the same unfavourable circumstances which led to the 
extinction of the race. 
EXPLANATION oF PLATES. 
Prats XXII. 
Fig. 1. Belemnites otapiriensis, sp. nov. 
Fig. 2. Belemnites aucklandicus, Hauer. 
a. ventral, b. lateral aspect. 
Fig. 3. Siam catlinensis, Sp. nov 
lateral, b. ventral aspect. 
Fig. 4. seemed hochstetteri, sp. nov. 
a. lateral, b. ventral aspect. 
Puare XXIII. 
Belemnites australis, Phillips. 
Var. a. a’. dorsal, a". lateral aspect. 
a^. longitudinal section. 
s’. transverse section of phragmacone. 
n 
Var. 3, V'. lateral aspect, b”. longitudinal section. 
E, T iaia section 2 phragmacone, 
ar 
Var. y. c VPE E dier riety 
c'", longitudinal section of alveolus. 
Var. 6. d'. ventral aspect, d". longitudinal section, showing ex- 
foliation of the central core, d". lateral aspect. 
s'. transverse section of guard. 
do. of phragmacone. 
Var. £. e’. dorsal, e". lateral aspect. 
e". dorsal, e” lateral. aspect, juv. 
s’. transverse section of guard. 
‘x. do. of pounems, juv. 
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