U iN I . 



Coi 



■ipccies 401. (ilus. Hanlev.) 

 Ni's. Uii. (estdobloiiijd, viihh; inmjiiHalerali, 

 (iiitice anijndald, podice prodiictd el siihrmtratd, 

 uepinn di'premt, tiii/rd cuncolore, lavi, margine dursali 

 /m-Hlicr) siibacclii'i, margine venlrali mbrelnso, cosid 

 lu/iljuiiiili bicouxpicud, area e.vtremd podicd coiieavd, 

 liniuld nulla, unibonibus erosis, hand cuiitien(ibi!.s, 

 iiiargaritd albidd, superni aiilem livldd vel liiteo-sub- j 

 olwaced, denUbus cardinalibiis vuc lumiiKill's, pontico 

 in vnlvidd dexlrd satis magna, satis valida, laciniatn, 

 itiigiihili). ' 



Couhik's Unio. Shell oblong, very iiiccii 

 rowed in front, produced and sonic 

 behind, iisii;dly depressed, of an unif'oi 

 sculptured, hinder dorsal margin soni 

 ventral edge somewhat indented, unibi 

 conspicuous, umbonal slope concave ; ni 

 not prominent, nacre whitish, but livid or yellowish- 

 olive above ; primary teeth scarcely lamellar, hinder 

 one of the right valve moderately large, strong, jagged, 

 and angular. 

 Lea, Tr:ui-<. Amer. I'h. Soc. vol. v. p. f..', (()b~. vol. i.) 



pi. 11. r :2.V 

 Hab. Pegu (W. Theobald). 



Of this species, which although closely allied to ii/argi- 

 uulis is yet easily distinguishable from its dentition, Lea has j 

 figm-ed a young specimen. The example here delineated, 

 being somewhat aged, is thicker and less depressed than 

 usual ; its lateral teeth are a little curved and somewluit 



llal.-ral, nar- 

 ivhat biMk.'d 

 m black, not 

 jwhat rising, 

 nal ridge not 

 iboes eroded. 



Species 402. (Mus. Ilanley.) 



I'NIO Klin'L.'\M)lANns. Uu. tesid siibquadrutd, validd, 

 uiitiri' pcrhrevi, postioe lale biangulald, ad umboues 

 hiagis miniisvcveutricosn, alibi depressd,ftiSco-olivaced, 

 siipente liiieis brevibiis saluraliuribns obscure radiatd, 

 siibLi'viijutd, siilci-1 iiicremeiili lanlum sculptd, mar- 

 gins lig/iwenldli rix declivi, margine veulrali anlici 

 acclivi, casta iiiiihonali satis conspiacd, ared dorsali 

 posticd, Idlii. mil Oil nib lis niodice eminentibits, margaritd 

 ulhd. iiiai-gnii- nirdinali latissimd, dentibiis cardinalibus 

 irigoiiis, laciiiialis. 



Kirti.aNd's L'NK). Shell sfpiarish, strong, very short 

 in IVciut, broadly biangiilated behind, depressed except 

 at the more or less ventiieo^e lunboes, olive-brown. 



faintly marked above with short linear darker ray>. 

 smoothish, merely sculptured by the grooves of in- 

 crease, ligamcntal edge scarcely sloping, ventral 

 margin rising in front, umbonal ridge tolerably con- 

 spicuous, umbonal slope broad, umbocs moderately 

 projecting, nacre white, hinge-margin very broad, 

 primary teeth triangular and jagged. 



Lea, Trans. Amcr. Ph. Soc. ser. 2. vol. v. p. 9S (Obs. on 

 Uiiio, vol. i.) pi. 14. f 4L 



TM. Ohio, N. America. 



In this species, allied to siibrolitiidiis of Lea, but flatter 



and darker, the epidermis is somewhat membranaceous. 



Species 403. (iLis. Ilanley.) 



Unio excavatus. Un. testd subtrigond, haud rrassii, 

 ralde injtntd, siibaijnilalerali, antice subplicatd angiistd 

 et porrertii, poslice nngidald et IcEvi, nitidissime luted, 

 vel eoiiculure, vel lineis olivaceis siibiiilerriiplis puslirr 

 radiatd, margine venlrali arcuaiu, umlio,nhiis hiii.-'inie 

 eminenlibns, natibus oblii/iiis, costd ninliiuiiili iiiigiilutii. 

 ared poslicd exireind planidatd, ligamenlo breci, mar- 

 garitd albidd, dentibas cardinalibus conico-compressis. 

 dentibiis laleralibus magnis. 



The hollowed Unio. Shell subtriangular, not thick, 

 nuich swollen, nearly equilateral, narrow projecting 

 and somewhat plicated in front, angular and smooth 

 behind, of a polished dirty yellow, either without 

 variegation or with indistinct somewhat iaterrupteil 

 olive-green linear rays on the hinder side, umboes 

 remarkably prominent, beaks slanting, umbonal ridge 

 angidated, the slope behind it flattened, ligameiil 

 short, nacre whitish, cardinal teeth conic yet coni- 

 jiressed, lateral teeth large. 



Lea, Obs. on Uido, vol. vi. p. 71. pi. 13. f. 52. 



Ilab. Georgia and Alabama, N. America. . 



The hinder profile is heart-shaped, and the radiating 

 concavity behind the umbonal slope leaves, by its indented 

 termination, a decided hiatus. Both primary and lateral 

 teeth are large; the formi-r are double in both valves. 



Species 404. (Mus. Ilanley.) 

 Unio atrocostatus, L'n. tcsid wngnd, solidd, siibr/ii 

 bed, maxiini incei/iiiluteruli, vcntricosd, oltvaccd c 



