~I 
PACE: ANATOMY OF VOLUTA MUSICA, LINN., ETC. 4 
as to appear quite membranous, and the lumen of the gut is at the 
same time increased. 
Salivary Glands.—Two pairs of so-called salivary glands are present 
(Fig. 7); the one pair acinose, the other tubular. Both pairs are 
situated entirely in advance of the central nervous system. 
The acinose glands occupy a position immediately in front of the 
nerve-ring. Their acint are much mixed up, but they are so 
exceedingly brittle that I was unable to determine whether there is 
any actual communication between the glands of the right and left 
sides, such as exists in certain Toxoglossa. The racemose glands 
are in close contact with the cesophagus, and only an extremely 
short tract of their ducts is free. After becoming applied to the 
cesophageal wall the salivary ducts become exceedingly delicate, so 
delicate that I was quite unable to follow them forward to their 
pharyngeal openings. 
The tubular glands are highly developed. That part outside the 
introvert is of large calibre, and les perfectly freely within the body- 
cavity. As is the case in V. musica, the tubular glands are sharply 
bent back upon themselves at a short distance from their distinctly 
enlarged distal extremities. ‘lhey are of gradually decreasing calibre, 
and become very delicate within the introvert. Upon re eaching the 
end of the radula-sac, the glands, now of extreme tenuity, pass 
under the retractor muscle of the buccal mass, and there unite to 
form a single convoluted duct of increased calibre. This convoluted 
duct forms a broad strap-shaped mass lying beneath the buccal mass, 
and might very easily be mistaken for an anterior buccal retractor. 
It was “possible to trace the duct right forward as far as the lips; 
and it appeared to open into the mouth well in advance of the buccal 
mass, but | was not able to make out its actual orifice with certainty ; 
anyhow, unless the duct doubles back again and 1s excessively delicate, 
it certainly does not open upon the floor of the buccal mass, as has 
been described, possibly erroneously, in other forms. 
Radula.—The radula contained 65 rows ; ; and the most important 
point which I bave been enabled to make out with regard to this 
interesting form is the fact that the true formula of the radula 
(Fig. 8) is 1-1-1, and not 0-1-0 as described’ by Sowerby (11). 
I had rather anticipated finding some indication of lateral teeth in 
this form, which in the characters of its shell and operculum approxi- 
mates rather towards the fusoid type; and therefore took particular 
pains in the investigation of this structure, otherwise its true nature 
would most certainly have escaped me. In the fresh state*® the lateral 
1 Sowerby’s figure shows such discrepancies from my preparation, that I venture to 
question whether the radula of some other species, e.g. Cymbiola ancilla, may 
not have been accidentaily substituted for that of eae by the mounter 
ot Sowerby’s slide. 
2 A radula should in all cases be examined Jefore cleaning with potash, since vestigial 
teeth such as those in question may be much too tender to withstand the action 
of this reagent. It is not sufficiently realized that potash is not without effect 
upon chitinous material; but that, on the contrary, delicate structures may be 
entirely destroyed by its use. 
