NATURAL SCIENCES OF PHILADELPHIA. 133 



Description of five New Species of the Genus UNIO. 

 BY ISAAC LEA. 



Unio SiAMESsif. — Testa laevi, transversa, subcylindracea,ad basim emarginata, 

 valiie infequilaterali, subcompressa, ad latere planulata, postice truncata, antice 

 rotundata ; valvulis tennissimis, diaphinis ; natibus prominulis ; epidermide 

 luteo-oliva ; dentibus cardinalibus acicularis, sublonoris, obliquis ; lateralibus 

 longi?, laraellatis suhrcctisque ; margarita alba et iridesceate. 



/7a6.— Siam ; C. M. Wheatlej. 



Unio asperulus. — Testa plicata, elliptioa, inaequilaterali, postice subbiangu- 

 lata, antice rotundata; valvulis subtenuibus; natibus snbprominentibus, ad 

 apices undulatis ; epidermide viridi-oliva, obsolete radiata ; dentibus cardinali- 

 bus lamellatis, parum obliquis, in dextro duplicibus; lateralibus sublongis, 

 lamellatis subcurvisque ; margarita cterulea et valde iridescente. 



Hab.—SlAm ; Thomas R. Ingalls, M. D. 



Unio pilatus. — Testa loevi, elliptica, valde inaequilaterali, postice obtuse 

 angulata, antice rotundata ; valvulis crassiustulis, aotice crassioribiis ; natibus 

 snbprominentibus, ad apices minute undulatis ; epidermide luteo viridi, 

 micanti, obsolete radiata ; dentibus cardinalibus duplicibus; lateralibus sub- 

 longis, subrectis lameJlatisque; margarita alba et valde iridescente. 



Ilab. — Siam ; Thomas R. Ingalls, M. D. 



Unio evitatos. — Testa laevi, elliptica, valde inffiquilaterali, postice subbiangu- 

 lata, antice rotundata; valvulis subteuuitius, antice parum crassioribus ; nati- 

 bus prominulis, ad apices divaricate undulatis; epidermide olivacea, obsolete 

 radiata; dentibus cardinalibus parviusculis, compressis, in ulroque valvulo 

 duplicibus; lateralibus sublongis, subrectis lamellatisque ; margarita alba et 

 iridescente. 



Hub. — Bengal ; AV. A. Haines. 



Unio Strebelii. — Testa laevi, oblonga, ad latere corapressa, inaequilaterali, 

 postice obtuse angulata ; antice rotundata ; valvulis subcrassis, antice aliquanto 

 crassioribus; natibus prominulis; epidermide luteo-fusca, radiata ; dentibus 

 cardinalibus subcrassis, elevatis, crenulatis, in utroque valvulo duplicibus ; 

 lateralibus sublongis, subcrassis, subcurvatus corrugatisque ; margarita vel 

 purpurea vel salmonea et valde iridescente. 



Ilab. — Vera Cruz, Mexico ; G. Strebel. 



Description of two New Species of the Genus LITHASIA. 

 BY ISAAC LEA. 



LiTHASiA cvLiNDRicA. — Testa Striata, cylindrace<», flavescente, vittata vel 

 evitata ; spira subelevata ; suturis irregulariter impressis ; anfractibus coo- 

 strictis, ultimo grandi ; apertura subconstricta, rhomboidea ; labro aculo 

 sinuoso; columella alba et valde sinuosa. 



Hub. — Coosa river; E. R. Sbowalter, M. D. 



LiTHAsiA Wheatleyi.* — Testa liBvi, subcylindracea, luteo-virente, vittata ; 

 spira elevata ; suturis 'irregulariter impressis, anfractibus planulatis, ultimo 

 subgraudi; apertura subconstricta, rhomboidea, intus vittata; labro acuto, 

 sinuoso; columella alba et volde iridebcente. 



Hab. — Cahaba river, Alabama, E. R Showalter, M. D. 



* Named after Mr. C. JI. Wheatley, to whom I am indebted for the possession of a specimen 



1866.] 



