ABNEOO DORN: 
Pate IX, 
Species 20. (Fig. 19, Mus. Cuming in Brit.) 
ANODON COMPLANATUS. An. testd latd, perobliqud, sub- 
ovatd, complanatd, levigatd, pallidé olivaced, fusco 
concentricé fasciatd, postice obscure radiata, intis 
albd, opacd ; latere antico brevissimo, angusto, ter- 
mino rotundo ; latere postico expanso, peroblique bian- 
gulato, infra angulos acuminato, supra angulos in 
alam compressam expanso, margine dorsali elevato, 
margine ventrali sursim acclivi. 
FLATTENED ANoDON. Shell broad, very oblique, 
subovate, flattened, smooth, pale olive, concentrically 
banded with brown, posteriorly obscurely rayed, 
THE 
white, opaque within; anterior side very short, nar- 
row, rounded at the end; posterior side expanded, 
very obliquely biangular, acuminated below the 
angles, expanded into a flattened wing above the 
angles, with dorsal margin elevated, ventral margin 
sloping upwards. 
ZIEGLER. 
Hab. Fox River? 
Species 21. (Fig. 20, Mus. Cuming in Brit.) 
Anopon Moretontants. 
nigrescenti, levigald, crassé, intus medio opacd, mar- 
An. testd angusta, oblonga, 
ginibus tridescentibus ; latere antico brevissimo, ter- 
mino rotundo, margine ventrali rectiusculo ; latere 
postico elungato, acuminato, supra angulum terminalem 
caring angustd distinctdé radiato, supra carinam in 
alam trigonam angustam expanso, medio tumido, mar- 
gine ventrali subangulato, umbonibus undulatis. 
Moreton’s ANODON. 
black, smooth, thick, within opaque in’ the middle 
and iridescent at the margins; anterior side very 
Shell narrow, oblong, rather 
short, rounded at the end, with ventral margin ra- 
ther straight ; posterior side long, acuminated, rayed 
with a narrow, distinct keel above the terminal angle, 
expanded into a thrce-cornered narrow wing above 
the keel, middle tumid, with the ventral margin 
almost angular, umboes undulated, 
Lza, Obs. Unio, i. p. 192. pl. xiii. f. 37. 
Hab. River Parana, S. America. 
This thick shell, with opaque nacre in the centre, is 
brilliantly iridescent at the margins within. The exterior 
is remarkable for a small rounded keel in place of the 
usual angle. 

Species 22. (Fig. 21, Mus. Cuming in Brit.) 
ANODON Susannaw. An. testd tumidd, crassa, ovato-sub- 
cuneiformi, levigald, concentricé strigatd, viridi, ver- 
sus margines intense olivaced, posticé strigis viridi- 
bus angustis radiata, intts albido-margaritaced ; la- 
tere antico contracto, valde hianti, imargine dorsali 
declivi, angulato, umbonibus obscure undulatis ; latere 
postico expanso, tumido, paulo hiante, obscure an- 
gulato, margine ventrali infra concavo, versus ter- 
minum sursiim acclivi, margine dorsali in alam sub- 
angulatam elevato, margine laterali declivi, umboni- 
bus inflatis. 
Susanna’s ANopoN. 
neiform, smooth, concentrically striped, green, in- 
tensely olivaceous towards the margins, posteriorly 
rayed with narrow green stripes, pearly-white within ; 
anterior side contracted, widely gaping, with dorsal 
margin sloping, angular, umboes obscurely undulat- 
Dp 
Shell tumid, thick, ovato-subeu- 
ing; posterior side expanded, tumid, slightly gaping, 
obscurely angular, ventral margin concave below, slop- 
ing upwards to the end, dorsal margin raised into a 
somewhat angular wing, with sloping lateral mar- 
gin, wmboes inflated. 
Grirritus, Animal Kingdom, tab. 24. f. 1. 
Hab. Rio de la Plata. 

Species 23. (Fig. 22, Mus. Cuming in Brit.) 
Anopon WaAHLAMATENSIS. 
expansi, subquadratin ovata, laevigata, distanter con- 
An. testaé subcomplanata, 
ceutrice rugatd, obscure olivaced, strigis linearibus 
fusco-viridis concentrice ornata, intus albidd ; latere 
antico brevi, angustato, medio depresso, umboni- 
bus parvis, depressis; latere postico expanso, sub- 
rostrato, distanter biangulato, inter angulos truncato, 
supra angulos area compressd alato, margine dorsali 
elecato, angulato, margine laterali prope anguluin 
concavo. 
THE WaHLAMAT ANODON. 
subquadrately oval, smooth, distantly concentrically 
wrinkled, dull olive, concentrically ornamented with 
brownish-green linear stripes, white within ; anterior 
side short, narrow, middle depressed, with small de- 
pressed umboes; posterior side expanded, rather 
rostrated, distantly biangular, truncated between the 
Shell rather flat, expanded, 
April, 1867. 
