6 



CONCHOLOGIA EVDICA. 



PLATE XI. 

 UNIO. 



1. U. favidens, Benson, An. Nat. Hist. ser. 3, 

 vol. 10 (1862), p. 188, for Glean. Sci. Calcutta, 

 vol. 1, pi. 7, f. 1 (-without name). — Reeve, Conch. 

 Icon. Unio, f. 131. 



Sunderbund, Bengal. 



The species was not actually described until Septem- 

 ber, 1862. 



2. U. favidens, var. pinax. — U. pinax, Benson, An. 

 Nat. Hist. ser. 3, vol. 10 (1862), p. 192. 



Gungun Stream, near Moradabad, Rohilcimd. 

 Figured from the worn type lent by Mr. Benson. 



U. favidens, var. plagiosoma. — U. plagiosoma, 

 Benson, An. Nat. Hist. ser. 3, vol. 10 (1862), 

 p. 191. 



River Cane, near Banda, Bundelcund. 



The beaks are eroded in the Bensonian type here 

 figured. 



•1. U. Sikkimensis, Lea, Proc. Philad. 1859, p. 151; 

 ()l)s. Unio, vol. 7, p. 69, pi. 39, f. 131.— Reeve, 

 Condi. Icon. Unio, f. 400. 

 Sikkim. 



This is in a better condition than Mr. Hanley's 

 original type of the species. 



.'». U. criapisulcatus, Benson, An. Nat. Hist. ser. 3, 

 vol. 10(1(S(;2), |). 193. — Reeve, Conch. Icon. Unio, 

 f. 2G2. 



Tonasaerin* ; Pegu. 



6. U. trirostris, Benson (not Reeve), in Hanley's 

 Phot. Conoli. pt. 1 (1802). 

 Moradabad. 



This well niarkcd form wns dishibutcd by Mr. 

 Benson ns his U. trirostris (a imuvo, like very many 

 other of his nmnuscript specie?) never actually published 

 by himself The specimen delineated in the Photo- 

 grnphio Conchology had been prcviovisly sent to Dr. 

 Lea, who regarded it as new to science. It may pos- 

 sibly prove A more variety of trinnbohts or favidens. 



PLATE XH. 

 UNIO. 



1. U. pachysoma, Benson, An. Nat. ser. 3, vol. 10 

 (1862, Sept.): separate, p. 3. 



Berhampooter River, Assam. 



A much more solid and rare shell than ihe allied 

 cceruleus. In England the only known specimens 

 are in the collections of Benson and Hanley. The 

 Calcutta specimen referred to by Benson is merely a 

 cservdeus. 



2. tr. Gerbidoni, Eydoux and Souleyet, Guerin's 

 Mag. de Zool. 1838, pi. 118, f 2. 



" Coromandel." 



Almost runs into ccErideus ; in characteristic ex- 

 amples, however, the anterior side is longer in propor- . 

 tion. It is not common. 



3. TJ. cseruleus, Lea, Trans. Amer. Phil. Soc. vol. 4 

 (Obs. on U. vol. 1, p. 105) pi. 13, f 25.— Hanley, 

 Recent Bivdve Sh. p. 194, pi. 20, f. 49.— Reeve, 

 C. Icon. Unio, f. 230. 



River Hooghly, »S:c. &c. 

 •1. U. Gerbidoni, variety, Eyd. and Soul. 



5. U. theca, Benson, An. N.at. Hist. ser. 3. vol. 10 

 (1862, Sept.) : separate, p. 3. 



River Cane, near Banda, Bimdelkund. 



Our drawing is tiiken from the unique example in 

 Mr. Benson's collection. The specimen seems scarcely 

 matxire, and bears some small resemblance to the young 

 of one of the tiianjinalts group, 



6. TJ. leioma, Benson, An. Nat Hist. ser. 3, vol. 10 

 (1802, Sept.), p. 192 : separate, p. 9. 



Near Bombay. 



We have figured two shelU one the aged and 

 eroded type of Benson, the other with the apical 

 sculpture perfect. It approaches ca>nileus, &c., very 

 closely. 



