of the varieties of TJ. cceruleus, Lea. I t is easily distinguished from TJ. bonne midi
by its more irregular shape, thinner texture, by the acute angulation, greater production
posteriorly, and by the more developed sculpture ; a constant character also
is the pink colour of the nacre, which in TJ. boimeaudi is bluish-white ; this is
equally distinct and characteristic in young as in old specimens.
Type from Myadoung ; long. 32, lat. 15^, crass. I l f mm.
Specimen of TJ. bonneaudi from Myadoung ; long. 31, lat. 18, crass. 13 mm.
Ymmly—CTRENIDM
Genus Corbiotjla, Meg.
CORBICTJIiA LAMARCKIANA, Prime.
CorUcula lamarchana, Prime, Ann. Lye. N. York, 1867; Nevill, I. c., p. 40.
Specimens obtained at Hotha and Momein (6,500 feet) in Yunnan, and also at
Mandalay, agree exactly with Prime’s original figure. Lieutenant-Colonel Godwin-
Austen also found a small .form of this well-marked species at Manipur, in the
Kuchai stream.
Long. 28|, lat. 20^, crass. 13 mm.
CORBICTTLA VUNNANENSIS, Nevill.
Corbieula yunnaneusis, Nevill, Joum. As. Soc., Bengal, vol. xlvi, 1877, p. 40.
Medium-sized specimens from Yaylaymaw agree fairly with Prime’s figure and
description of C. lirmema,1 the principal difference being the less truncate anterior
Fig. 32.
Corbieula yunnamensis, nat: size.
side. Shell large, thick, transverse, inequilateral, compressed, rather abruptly tumid
towards the umbones; anteriorly moderately produced and rounded, posteriorly
produced and truncate (exactly as in Prime’s figure of O. linnecma) ; lateral teeth
curved, the anterior a little more so than the posterior; no lunule; epidermis dark
brown, striae regular and close; interior violet, of a darker shade near the margin.
1 Ann. Lyc. N . York, 1867.
This species is more inequilateral, more tumid near the umbones, and more regularly
sulcated than C. mulleriana, Prime (loc cit) from China, which, however, it also
closely resembles.
Type from Manwyne in Yunnan (4,000 feet); long. 39, lat. 33 mm.
Yaylaymaw (all young), long. 21£, lat. 17, crass. 11£ mm.
COBBICULA ANDEBSONIANA, Nevill.
Corbieula audersoniana, Nevill, Joum. As. Soc., Bengal, vol. xlvi, 1877, p. 41.
Rather small, thin, subequilateral, transversely ovate, tumid; medium-sized
specimens closely resemble in shape C. mcequilateralis, Prime; both sides are obtusely
rounded, epidermis bright green, interior violet, paler near the margin. This is
quite distinct from the other Burmese and Indian species; it is, however, exceedingly
close to C. tumida, from Borneo, as figured by Issel.1
Type from Momien in Yunnan; long. 20£, lat. 12 mm.