Hurton.—On the Fresh-water Lamellibranchs of New Zealand. 149 
think, distinct, although some specimens are difficult to distinguish from 
U. menziesii. I have not examined the animal.’ U. hochstetteri I have 
never seen. 
Notes on the animal of U. menziesii,—Pl. IL., figs. a, B, c, and p. The 
anal siphon is dark purple outside and yellow inside; the orifice is simple. 
The region of the branchial siphon has numerous cirri, some of which are 
dark purple, others yellow ; inside the shell the margin of the mantle is 
speckled with yellow pigment spots. The branchiw are yellow-brown in 
colour, the outer darker than the inner one. They are attached at their 
posterior extremities to the mantle below the anal siphon, but are free from 
this point to the posterior adductor. The outer branchia is attached to the 
mantle throughout its whole length, and is obliquely truncated anteriorly ; 
the inner branchia is not united to the foot. The foot is large, and its 
anterior and lower portions, which are not covered by the branchie, are 
slate grey in colour. The labial palpi are white, speckled with yellow, their 
length is about twice their breadth, and for about half their length the two 
on each side are united posteriorly. All the nervous ganglia are white, but 
show nothing remarkable in shape or position. The heart makes fifteen 
beats a minute. The alimentary canal is remarkably simple; from the 
capacious stomach it runs along the lower side of the body cavity to the end, 
and then turns abruptly upward and forward to the stomach, from whence 
it ascends to the heart. A crystal-style is sometimes present. The animal 
is dicecious. I have found both spermatozoa and ova in the month of June. 
CyreNnIpz. 
In the Catalogue of the “Conchifera in the British Museum,” and in 
the ‘Proceedings of the Zoological Society of London” for 1854, M. 
Deshayes has described a Spherium nove-zealandiea, which has been also 
figured by Reeve. It is a small species of a bluish-grey colour ‘‘ abundantly 
irregularly transversely banded ;”’ and is said to come from New Zealand 
and Australia. I have never seen a shell answering to this description, 
and the New Zealand habitat may perhaps be erroneous. 
In the “ Malakozoologische Blatter” for 1861, Dr. Dunker described a 
Spherium lenticula from specimens brought to Europe by Dr. v. Hochstetter 
from Lakes Rotoiti and Taupo. This little shell (pl. IL., fig. x) is common 
throughout New Zealand; but it is a Pisidium, and not a Spherium. 
Usually it is nearly equilateral (fig. z.a.), but occasionally very inequi- 
lateral (z.b.). The two forms are, however, only varieties of one species, 
as intermediate varieties completely connecting them are found in the same 
locality. At least both forms and intermediate varieties live together near 
istchurch. The longer side of the shell is anterior. The siphons are 
very short, and completely united, the margin is simple. The foot is long 
