276 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 
may be an individual peculiarity) agrees with Mr. Daly’s specimens. 
A shell, however, belonging to Mr. Ponsonby, which, he informs 
me, is an authentic specimen of A, Dugasti, although distinguished 
by a higher spire, is, I think, clearly a variety of the Upper Siamese 
form. The latter I describe as follows :— 
Testa subobtecte perforata, depresso-globosa, pallide fulvo-cornea, 
levis, nitida, vix striatula; spira convexa vel depresso-conoidea, apice 
obtuso, suturaimpressa; anfr. 7, convexi, lente accrescentes, ultimus ad 
peripheriam rotundatus, antice paululo descendens, subtus tumidus ; 
apertura obliqua, lunaris; peristoma obtusum, albidum, margine dextro 
sinuato, basali subrecto, vix arcuato, columellari expansulo, ad 
insertionem in laminam triangularem desinente. Diam. maj. 14, 
min. 13mm.; alt. 10 mm. 
In some specimens the upper surface is darker-coloured than the 
lower, and the junction of the two shades at the periphery of the shell 
is marked by a fine groove which does not extend all the way round. 
This character is found in only a few specimens, and is doubtless 
accidental. There is considerable variation in the height of the spire. 
In the slightly thickened peristome and the slight arcuation of its 
basal margin, this shell shows a considerable resemblance to the 
Burmese JL, petasus (Bs.), which, however, has not the globose form 
of I, Dugaste. 
The shell of one specimen contained the dried-up animal; and this 
I sent to Colonel Godwin-Austen, to whom I am indebted for the 
following details.. He succeeded, after soaking the dried mass, in 
ascertaining that the sole of the foot was divided longitudinally into 
three areas; there were the usual peripodial fringe and grooves, and 
a short overhanging lobe above the mucous pore. There was apparently 
a right shell-lobe, but this could not be distinctly made out, nor could 
it be ascertained whether a left shell-lobe was present. The long 
flume of a spermatophore was found, indicating that the spermatheca 
must be very long in this species. After much soaking the jaw and 
radula were found. The jaw is curved slightly, but has no median 
projection on the cutting edge. The teeth of the radula are arranged 
in rows of 40:2:9:1:9:2:40(51: 1:51) teeth. The median 
tooth is tricuspid, the inner laterals, or admedians, have each a single 
cusp on the outer side, the marginals are minute and bicuspid. On the 
whole the characters agree sufficiently with Macrochlamys to render 
it probable, in Colonel Godwin-Austen’s opinion, that JZ. Dugasti 
belongs to that genus. 
The original locality of IZ Dugasti was said to be in forests on the 
banks of the Menam Pinh, Western Laos. The Menam Pinh is 
probably the same as the Me Ping, shown in maps as running near 
Chieng Mai. 
§. Macrocutamys anceps (Gould). 
Two small specimens of a shell which I take to be a variety of this 
species were sent to me in the first collection I received from Mr. Daly. 
A third occurs amongst the shells received by Mr. Preston. One of 
them, apparently adult, measures only 12 by 11mm. in the two 
