Hectok. — On the Belemnites found in New Zealand. 485 



8. NoToccELi. — a. Notosipldti : Fusiform, 'witli a dorsal groove, sijplitincle 

 on dorsal aspect, aud lateral furrows, h. Gastrosipldti : Subcylindrical, 

 with siphuncle on ventral aspect, and short lateral grooves, (Lower 

 Cretaceous.) 



Unless it be by certain forms in the liassic strata of the Hokanui and 

 Kaihiku ranges of Southland of which only the large phragmacones have 

 been preserved, the first of these groups has no species in New Zealand 

 representing the Clavati of Europe. 



In the second group, which includes the sub-groups Canaliculati and 

 Hastati, there are several species found in the Putataka formation, both in 

 the North and South Islands. 



The great majority of forms found in New Zealand belong to the third 

 group, but only to its second section, the first section, representing the 

 Dilatati of the European neocomian formations, not being present in our 

 collection. They are very common in the Amuri series, which is equivalent 

 to the lower greensand, and is remarkably rich in belemnites in a perfect 

 state of preservation, but they also survive to the horizon of the upper 

 greensand. 



The New Zealand forms of this subdivision are characterized by the 

 absence of any ventral or dorsal grooves, by a variable form — being cylin- 

 drical, hastate, or depressed — by the constant presence of short lateral 

 grooves on the upper part of the guard, and the ventral position of the 

 siphuncle that traverses the septa of the phragmacone. 



There are five well-marked varieties that might be considered as speci- 

 fically distinct were they not so intermixed in the same strata. I have 

 referred these to M. Duval- Joave's subdivision GastrosiphUi of the neocomian 

 belemnites, on account of the position of the siphuncle, which is probably 

 of more anatomical significance than the grooves on the external surface of 

 the guard ; but in the European species a dorsal groove is always present, 

 whereas it is absent in all the belemnites I would associate in this group 

 from the lower cretaceous formations of India, Australia, and New Zealand. 



Group I. — AccELi. 



1. Belemnites otapiriensis, sp. nov. 



PL XXII., fig 1. 



Guard unknown, being only represented by a crushed mass having a 

 longitudinal fibrous structure. Phragmacone with from twenty to thii'ty 

 septa, shghtly elliptical in form, outline forming an angle of 15°. Siphuncle 

 marginal on the major transverse axis, the septa being inserted round the 

 aj)erture so as to form almost a continuous tube traversing the sejota. 



This belemnite ranges through the Otapiri series (liassic) down close to 

 the horizon of the Monotis beds of the Wairoa series (triassic), and though 



