Hectok. — On the Belemnitcfi found in Xew ZealainL 489 



Belemuites first appear in the calcareous conglomerate, and constitute 

 the wliole 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 x^eculiar 

 forms which I have shown to result from the exfoliation of the perfect 

 guards, and no trace of a belemnite possessing the upper x^ai't 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. 



Plate XXII. 

 Fig. 1. Belemnites otapiriensis, sp. nov. 

 Fig. 2. Belemnites aucMandicus, Hauer. 



a. ventral, b. lateral aspect. 

 Fig. 3. Belemnites catlinensis, sid. nov. 



a. lateral, h. ventral aspect. 

 Fig. 4. Belemnites hochstetteri, sp. nov. 



a. lateral, b. ventral aspect. 



Plate XXIII. 

 Belemnites australis, Phillips. 



Var. a. a', dorsal, a", lateral aspect, 

 ft'", longitudinal section. 

 s'. transverse section of phragmacone. 

 s". do. of guard. 



Var, l3, i>'. lateral aspect, b". longitudinal section. 

 s'. transverse section of phragmacone. 

 s". do. of guard. 



Var. y. c' ventral, c". lateral aspect. 



c'". longitudinal section of alveolus. 

 Var. d. cV. ventral aspect, d" . longitudinal section, showing ex- 

 foliation of the central core, cV" . lateral aspect, 

 s'. transverse section of guard. 

 s" . do. of phragmacone. 



Var. £• e'. dorsal, e". lateral aspect. 



e'". dorsal, e"". lateral, aspect, jiff. 



s'. transverse section of guard. 



s". do. of phragmacone, juv. 



■^ l2 



