58 Transactions, — Zoology. 
EXPLANATION OF PLATE XII. 
Fig. 1. Limnea arguta. Shell and animal. 
Fig. 2. » ampulla. Shell 
Fig. 3. » leptosoma. Shell 
Fig. 4. »  tenella. Shell 
Fig. 5. »  pucilla. Shell : 
Fig. 6. Planorbis corinna. Shell and animal. 
Fig. 7. Bulinus variabilis. Shell. 
Fig. 8. Limnea ampulla. Dentition x 470. 
Fig. 9. » tomentosa. Dentition x 740. 
Fig. 10. E: arguta. Dentition x 470. 
Fig. 11. » tenella. Dentition x 740. 
Fig.12. Bulinus maesta. Dentition x 470. 
Art. VII.— Description of a new Species of Paper Nautilus (Argonauta 
gracilis). By T. W. Kirk. 
[Read before the Wellington Philosophical Society, 9th July, 1884.] 
ate : ; 
Tmar we have in New Zealand two species of the beautiful ‘ Paper 
Nautilus,” so called on account of the extreme delicacy of its shell, I have 
for some y 
Mr. C. H. Robson of Te Mahia, who had himself noticed the difference, for 
the loan of several examples which supply the links required to render the 
The larger serieg examined, the individuals of which range from 11-9 
inches across, undoubtedly belong to A. tuberculata, Shaw. The description 
given is defective, yet a comparison of the shell with drawings by Chenu, 
Reeve, and other authors, is conclusive. 
I propose to amend the deseription as 
sides with transverse plieations which are 
Aperture nearly square posteriorly, 
produced outwards so as to form 
beyond the sides of the shell. Keel 
brown on the spire, where also the 
follows :—“ Shell compressed, 
longitudinally tuberculiferous." 
margin much thickened, and the angles 
pointed wing-like processes, projecting 
8 two, with compressed tubercles, white, 
keel tubercles are blackish-brown. 
What I now consider to be a new species is distinguishable from the 
foregoing at a glance. The whole shell has a more graceful and regular 
outline, and is much more fragile looking, the aperture is narrower and 
rounded, especially posteriorly, there is no sign whatever of wing-like - 
expansions, indeed the sides have a graceful Sweep where the angle occurs 
