fe a 
15 
Testa ovata, tenuis, virescens, antice rotundata, postice obtuse 
angulata, margine dorsali postico convexiusculo, ventrali sub- 
stricto; angulus a vertice decurrens, aream posticam teste 
circumscribens ; ruge V-formes in medio teste, ascendentes in 
area postica, utreque in adultioribus obsolescentes. Dentes 
cardinales tenues, compressi, vix crenati ; lateralis elongatus, 
arcuatus, in valva dextra duplicatus. 
Long. 51, alt. 29, diam. 14 mill.; vertices in } longitudinis siti. 
The other species described and figured by Lea, /. ¢., are :— 
Unio hainesianus.—This is a large, convex, and rounded shell, 
with the wing well developed and almost rectangular to the longitude 
of the shell ; allied to U. housez, eumingii, and schlegelit. 
Unio eximius.—This has also a folded wing. 
Unio scobinatus.— Allied to U. rusticus, from the same locality, 
with the corrugations much more developed. 
Unio inornatus.— With two oblique keels on the hinder half of 
the shell. ; 
! Unio tumidulus.—Similar to the European U. tumidus. 
\ Unio sagittarius.—Nearly approaching the Egyptian U. cailliaudi. 
Unio humilis, substriatus, nucleus.—Founded on very small, per- 
haps immature shells. 
AnoponTa (subg. LaMPROSCAPHA) SCHOMBURGKI, m. 
Testa elongata, antice angustata, postice dilatata, compressa, 
tenuis, epidermide nitente, virescente tecta ; margo dorsalis sub- 
rectus, postice in alam humilem longiusculam elevatus ; margo 
anticus et posticus rotundati, angulis nullis distincti, margo 
ventralis subconcavus ; cardo plane edentulus ; impressiones 
musculares modice, accessoria antica modica subrhombea; facies 
interna violaceo-rubens. 
Long. 82, altitudo ad vertices 27, in parte postica dilatata 38, diam. 
15 mill., vertices ante + longitudinis siti. 
Misit Schomburgk. 
The thin and very flat shell and the want of edges at the margins 
render it impossible to associate this species with Spatha rostrata, 
and induce us to search for allied forms in the subgenus Lampro- 
scapha of Swainson. 
ANODONTA CALLIFERA, N. 
Testa rotundato-ovata, crassa, epidermide nigricante, margines 
versus tomentosa ; vertices non prominentes, approximati ; 
margo dorsalis antice angulatus, postice convecus, arcuatim 
descendens ; margo posticus perpendiculariter truncatus, anticus 
et ventralis valde arcuati; cardo callo marginali inflexo, in 
valva sinistra prominulo, dentiformi, in dextra emarginato- 
notatus ; impressiones musculares anteriores 2, altera (acces- 
soria) minor, reniformis. 
Long. 80, alt. 51, diam. 28 mill.; vertices in } longitudinis. 
