150 Transactions.— Zoology. 
and colourless. The animal is very active and moves about by means of 
its foot, much in the manner of a Gastropod. It lives not only in mud, 
but also on aquatic plants. 
Pisidium nove-zealandie was described by Prime in the ‘ Proceedings of 
the Zoological Society of London” for 1862, and afterwards in the ‘‘ Annals 
of the Lyceum of Natural History of New York” for 1867 with a wood-cut. 
This may be the same as the variety 6 of Pisidiwm lenticula, as the descrip- 
tion agrees very well; but if so the figure, judging from a tracing I had 
made for me, cannot be very correct, for that represents a nearly equilateral 
shell with a prominent umbo. The specimens described by Mr. Prime are 
said to have been brought from New Zealand by Mr. Cuming, so there may 
be a mistake in the habitat, as I believe Mr. Cuming never visited New 
Zealand. 
EXPLANATION OF PLATE II. 
A. Unio menziesii, with the foot expanded. c¢ anal siphon. 
B. Unio menziesii, left valve and mantle removed. a Anterior adductor muscle; 
b posterior adductor; c anal siphon; d foot; e¢ labial-palp; f branchiz. 
C. Unio menziesii, left side of mantle and branchie# removed, and the pericardium 
laid open. a Anterior adductor; 6 posterior adductor; d foot; e labial 
palp; f right branchia; g rectum; h heart; i cerebral ganglion; & parieto- 
splanchnic ganglia. 
D. Unio menziesii, body cavity laid open, showing the mouth, stomach and intes- 
tine; 1 pedal ganglia. 
E. Pisidium lenticula. a Type form; b variety. 
Art. XIX.—Notes on some Pulmonate Mollusca. 
By Professor F. W. Hurron. 
[Read before the Philosophical Institute of Canterbury, 2nd June, 1881.] 
Plates ITI. and IV. 
Parvuna coma, Gray. The jaw is slightly arcuate, with the ends attenu- 
ated ; it is marked with distant strie which converge slightly towards the 
upper margin. (Plate IIL., fig. x.) 
The radula is ‘01 inch in breadth. Teeth 13-1-18, of which 6 may be 
called laterals. The central tooth is tricuspid, the side cusps short and 
ronnded and without cutting points, the median cusp long and narrow Wi 
a small cutting point at the extremity ; the base of attachment is broad and 
rectangular, and extends beyond the cutting point of the median oo 
The lateral teeth are similar to the central, but the base of attachment is 
oblique. The seventh tooth has the cusps nearly equal, and the inner side 
