1877.] Upper Burma and Yunnan. 30 



Unio Bhamoensis, Theob. 



Unto Bhamoensis, Theob., J. A. S. B., 1873, p. 207, pi. 17, fig. 1. 

 Unio Mandelayensis, Theob., J. A. S. B., 1873, p. 208, pi. 17, fig. 2. 



Not uncommon at Myadoung and Yaylaymaw ; found also on the First 

 Expedition at Mandalay, Bhamo, and Sliienpagah. The two above forms can 

 certainly not be separated, as indeed might have been surmised from Mr. 

 Theobald's remarks in the original description, large series from one locality 

 showing that both varieties run one into the other. The Pegu form men- 

 tioned in the original description of TI. Bhamoensis differs a good deal more 

 from both than the Bhamo from the Mandalay one ; it is a pity Mr. Theobald- 

 did not give this Prome variety a name, instead of the Bhamo one. 



Ujs^io teagilis, n. sp, 



? TTnio foUaceus, Gld., Proc. Bost. Soc. ; Con. Indica, pi. 42, fig. 3. 

 ? JJ. Feguensis, Anth., Am. J. Con., pi. 25, fig. 2. 



Ten specimens from Yaylaymaw only differ from the Pegu form, in 

 that the epidermis, except on the posterior angle, is quite smooth ; unfortu- 

 nately they all seem young shells ; the two biggest are exceptionally tumid, 

 in this respect differing from the others, as also from the Bhamo and 

 Sheinpagah specimens ; in all of the above the nacre is less yellow-tinged 

 towards the umbones, and the teeth thinner than in U. foUaceus. It is 

 a form extremely close to, if not identical with, the TJ. comptus, Desh. 

 (Nouv. Archives X, PI. 6, fig. 3 — 4), stated by MM. Crosse and Fischer to 

 be the TJ. Sumatrensis of Lea. 



Type of TI. fi^agilis from Yaylaymaw : long. 34, lat. 17^, crass. 11^ 

 mil. 



Three specimens from Bhamo, all young : long. max. 43, lat. 24, crass. 

 13 mil. 



Thirty specimens from ShienjDagah, all young : long. max. 32, lat. 17, 

 crass. 9|- mil. 



Specimens of TJ. foliaceus, from Pegu, long. 58, lat. 22, crass. 17 

 mil. 



Unio pijgio, Bens. 



TTnio pugio, Bens., A. & M., 1862, p. 193 ; Con. Indica, pi. 10, fig. 7. 



Abundant at Myadoung, Bhamo, and Yaylaymaw. Very young speci- 

 mens are rugose anteriorly, especially near the umbones. 

 Long. 57, lat. 27, crass. 20 mil. 



Unio Bonneaudi, Eyd. & Soul., var. 



Unio Bonneaudi, Eyd. & Soul,, Mag. de ZooL, 1838, pi, ; Con. Indica, pi. 10, fig. 6, and 



pi. 46, figs. 5, 6. 



