478 Transactions. 
KEY то THE New ZEALAND SPECIES OF ATAXOCERITHIUM. 
Shell acicular, spire more than three times height of aperture .. A. suteri. 
Shall + 1 
ribs which are confined to base and interstices .. A. kuttoni. 
(2.) Axial ribs nodulous. 
(A.) Periphery sharply angled. 
Spirals equally nodulous. 
Axials rather weak and narrow -. A. pyramidale. 
Axials strong and wide ес -. A. pyramidale subsp. 
robustum. 
(B.) Periphery convex. 
(AA.) Four or more spirals per whorl. : 
(а.) Periphery regularly rounded, 
rather finely cancellate ap- 
pearance £s .. A. nodicingulatum. 
(b. Periphery  subangled, rather 
coarsely cancellate арреаг- 
ance vi y .. A. quadricingulatum. 
(BB.) "Three spirals per whorl Ne -. A. tricingulatum. 
Chione (s. str.) crassitesta n. sp. (Plate 50, figs. 1а, 1b, 1с.) 
Shell trigonally ovate, extremely swollen and solid, radial and concentric 
ornament prominent. Beaks very prominent, inflated, situate at anterior 
face, becoming subobsolete posteriorly (about 30 can be counted on the 
type; in C. stuchburii (Gray) they reach 40-or more) Very prominent 
foliaceous concentric ribs decussate the radial sculpture, are rather narrow 
(interstices two to three times their width), and are most strongly developed 
P 
Posterior adductor-scar slightly larger, but the anterior more sunken. 
Pallial line distinct, distant from margin, sinus short and acutely trigonal. 
ОЕР адаарга чаро ао eS 
: |O. st i (Gray) 
—— C. crassilesta nov. C. stuchburyi (Gray), ue ылу, е 
Normal Form. | Auckland Islands. 
: Length e: vd 47 mm. 47 mm. | 65 mm. 
Height .. х 43 mm. 40mm. | 50mm. 
Width (two valves) .. 43 mm. 20 mm. | 36 mm. 
.. Holotype, from Clifden, near Cape Kidnappers (Pliocene), in author's 
collection—collected by Dr. Benson. Paratypes in Otago University School 
of Mines collection, 
. 
Andr: ууз 
