1875.] MAJOR H. H. GODWIN-AUSTEN ON HELICID#. 43 
shortly to make them public. They are no doubt valid; and I shall 
conclude by observing that this ‘ Relation’ accordingly offers no evi- 
dence of the later existence of the Solitaire and other extinct birds 
of Rodriguez than we already had from the journal of Pingré kept in 
1761. 
5. Supplementary Notes on the Species of Helicide of the 
Subgenus Plectopylis. By Major H. H. Gopwin-Avsten, 
F.R.G.S., F.Z.8., &c., Deputy Superintendent, Topogra- 
phical Survey of India. 
[Received January 11, 1875.] 
Since I have been at Calcutta, I have looked over the specimens 
of Plectopylis in the Museum, and find some additional notes to add 
to my former paper, as well as a new species, which I now proceed 
to describe. 
He ix (PLECTOPYLIS) TRILAMELLARIS, N. sp. 
Shell sinistral, widely and openly umbilicated, discoid, flat above ; 
apex slightly raised, solid, covered with a brown epidermis, roughly 
and obliquely striated. Whorls 7, sides well rounded. Aperture 
oblique, widely lunate. Peristome white, much reflected and thick- 
ened, the margins united by a strong high ridge, reflected slightly 
forward, a slight notch separating it from the lower margin of the 
peristome. A single simple parietal vertical lamina is situated nearly 
one half of the circumference from the aperture, giving off from its 
lower end a long horizontal lamella, which extends halfway to the 
aperture ; the usual median horizontal lamella is not united to the 
vertical Jamina, but extends up to, and is united to the apertural 
parietal ridge, and is strongly developed. A third, thread-like free 
lamella extends also up to the aperture, having its origin just below the 
vertical lamina. The palatal plice are simple, six in number, the 
first and upper very short, the second very long, and the rest moderate 
and equal. 
LT ee ae ee an eae aes 0°65 
MEI NOPAGIAII Ag eal fk: lpbcabiaud <seataciee exter ds sealaepOROO 
IE SE RT SE Ss Ie PRET | 0). 
Hab. Burmah. Exact locality unknown; collected by Mr. 
Theobald, jun., of the Geological Survey of India. In the collection 
of the Indian Museum, Calcutta. 
On an examination, kindly assisted by Mr. G. Nevill, of the Indian 
Museum, Calcutta, of all the species of this genus, the above form 
turned up. It differs so much from P. perarecta, with which it is 
closely allied, that I do not hesitate to describe it as new. From 
that shell it differs internally in the upper horizontal lamella being 
