From the ANNALS AND MaGazinr oF Natura History, 
Ser. 6, Vol. xili., January 1894, 
On the Dentition of Pella Burnupi, Melvill and Ponsonby. 
By Henry Suter, Christchurch, New Zealand. 
| Plate V. B.| 
SomE time ago Mr. J. H. Ponsonby kindly sent me a number 
of Helicide from South Africa, and, on carefully examining 
them, I was astonished how some of them showed distinct 
relations to forms from New Zealand. Fortunately there was 
one specimen of Pella Burnupi, M. & P., in which the dried- 
up animal was left, and, after proper treatment, I succeeded in 
getting it out of the shell, leaving the tail well preserved. 
In preparing jaw and radula great care was used, as those 
parts of the mouth are often exceedingly fragile when the 
animal has been dry for a long time. The mounting of the 
radula was successful, but the jaw broke in several pieces, 
without, however, impeding the study of its detail structure. 
Jaw (Pl. V.B. fig. 1) arcuate, folded in about twenty 
vertical plaits, which are about five times longer than broad, 
and strongly transversely striated. Between the plaits a 
small transparent interstice is left. Cutting-margin broadly 
indented. ; 
Radula (fig. 2) tongue-shaped, consisting of numerous 
transverse straight rows of teeth, 20—1—20, of which five or 
six may be taken as laterals. 
Central tooth quadrangular, slightly longer than broad, 
rounded in front; reflexion tricuspid, the median cusp 
reaching almost to the posterior end of the base; the side 
cusps short, sinuated at the outer sides ; median cutting-point 
well developed, extending a little over the next row of teeth ; 
the side cutting-points minute. 
Laterals very much like the rhachidian, the median and 
