CONCHOLOGIA INDICA. 
5 
PLATE IX. 
SPATHA, PSEUBODON, TRIGOTJODON, 
UNIO. 
1. S. Soleniformis, Benson (as Anodon), Journ. 
Asi. Soc. Bengal, vol. 5 (1836, Nov.), p. 749. 
Cacliar. 
If this shell is a true Mycetopus, its specific name 
must be changed, as D’Orbigny published his M. Sole¬ 
niformis in 1835 (Guerin’s Mag. Zool.) : it closely 
approaches the M. (?) emarginatus of Lea. 
2. P. inoscularis, Gould, Proc. Bost. Soc. Nat. 
Hist. vol. 1, p. 160 (as Anodon), 161. — Unio 
Vondembuschiana, Reeve, Conch. Icon. Unio, 
i. 518, badly (from this specimen). 
River Salwen, Birmah. 
May possibly prove identical with the Margaritana 
Vondembuschiana (Lea, Trans. Amer. Phil. Soc. vol. 8, 
pi. 18, f. 39,) a supposed Javanese species. 
3. T. erebristriatum, Anthony, Amer. Journ. Clone, 
vol. 1 (1865), pi. 18, f. 1 (as Monocondylasa). — 
Unio c. Reeve, Conch. Icon. Unio, f. 517. 
British Birmah. 
4. P. Salwenianum, Gould, Proc. Bost. Soc. Nat. 
Hist. vol. 1, p. 158, 160 (as Anodon and Pseudo- 
don) : Otia, p. 193.—Unio S. Reeve, Conch. Icon. 
Unio, f. 513. 
Salwen River, Birmah. 
5. T. erebristriatum, var. Anthony. 
The Monocondylaa Peguensis of Anthony (Amer. 
Conch. Journ. vol. 1) seems a form of this rather 
variable species. 
6. U. lamellatus, var. Lea. 
A peculiar winged form (like Wahlamatensis of 
Lea) from Mandelay. 
Judging from the examination of many hundred 
specimens of Indian Uniones, confirmed by long and 
peculiar study of thousands of North American Naiades, 
we are compelled to believe that the teeth and muscular 
impressions of each species are so liable to modification 
through age and casualties as scarcely to present any 
permanent defining character. Not but that they 
merit examination, as the vividly green variety of 
triembolus can instantly be discriminated from corru- 
gatus by its dentition. 
According to our notions cceruleus , marginalis, favi- 
clens, corrugatus have been unnecessarily subdivided, 
and several species founded on diseased or eroded 
shells; but as our aim is to indicate the names which 
have been applied to the several forms, we shall pro¬ 
ceed to figure the more striking ones, never erasing a 
species from our lists without having traced it to its 
root by indisputable links. 
PLATE X. 
UNIO. 
1. Unio olivarius, Lea, Trans. Amer. Phil. Soc. 
ser. 2, vol. 4 (Obs. on Unio, vol. 1, p. 113), pi. 16, 
f. 38.—Hanley, Recent Bivalve Sh. p. 195, pi. 22, 
f. 32.—Kuster, ed. Chem. Unio, pi. 82, f. 2. 
Rohilcund Streams. 
2. 4. U. maeilentus, Benson, An. Nat. Hist. ser. 
3 (1862), p. 187.—U. occatus, Lea, Journ. Ac. 
Nat. Sc. Philad. 1863 (Obs. on Unio, vol. 10), 
pi. 50, f. 304.—Reeve, C. Icon. Unio, f. 412. 
“Bengal;” Mandelay. 
The somewhat worn condition of the type (figure 2) 
prevented Lea from identifying the species. 
3. U. radula, Benson, in Hanley’s Recent Bivalve 
Sh. p. 382, pi. 23, f. 41. 
Assam. 
Benson’s unique type (with part of the ferruginous 
coating removed), from which Mr. Hanley drew up his 
description, has been once more figured. 
5. U. smaragdites, Benson, An. Nat. Hist. ser. 3, 
vol. 10 (1862), p. 190. 
Burhampooter River, Assam. 
So rare a shell that the original types are the only 
examples known to us. 
6. U. Ronneaudi, Eydoux and Souleyet, Guerin’s 
Mag. de Zool. 1838, pi. 119, f. 1. 
Bhama, Upper Birmah (Blanford). 
A very scarce shell, lent to us by Mr. Blanford, 
Avhose incomparable series of Indian Uniones was most 
liberally placed at our disposal. 
7. U. pngio, Benson, An. Nat. Hist. ser. 3, vol. 10 
(1862), p. 193, Reeve, C. Icon. Unio, f. 516. 
Ava; Pegu (Theobald). 
A rare shell which cannot be confused with any 
other of the known Indian Uniones. 
