1G2 uniosidtE. 



ovata, valde inaequilaterali, crassa, subinflata, antice rotundata, 

 postice superne sensim descendente, demuiu obtusa, raargiiie 

 ventrali convexiusculo, postice A'ix emarginato ; disco Ifeviusculo, 

 concentrice leviter striatulo, antice obsolete radiato-striato, versus 

 iimrginem veutralem et posteriorem plicato ; epidermide olivaceo- 

 fusca ; umbouibus convexis, decorticatis, obsolete radiato-sulcatis, 

 apicibus proiuinentibus obtusis, remotiusculis ; luuula elongato- 

 elliptica ; ligaraento brevi ; dentibus cardinalibus crassioribus, 

 radlatira eroso - sulcatis, lateralibus obliquis, utriusque valvoe 

 duplicibus, subflexuosis ; margarita albida, iridesceiite. 



Long. 30, lat. 48, diaai. 21 mm. 



Anterior cicatrices subconfluent, posterior entirely so, apical 

 ones under the cardinal tootb ; cavity of the beaks very deep. 



Hah. Gungun River, near Moradabad, Eohilkliund. Specimens 

 in the Indian Museum from Arrah. 



A very distinct cuneiform variety. 



Yar. plagiosoma {Benson). 



Unio jylayiosoma. Benson, A. M. N. II. x, 1862. p. 191. 

 Unio favidens, var. jylayiosoma, H. &; T., C. 1. 1876, p. 6, pi. 11, 

 fig. 3. 



Original description : — Testa transverse trigono-ovata, inaequi- 

 laterali, crassiuscula, tumidiuscula, antice rorundata, postice sub- 

 convexe declivi, demum obtusa, margine ventrali convexiusculo ; 

 disco obsolete plicato, epidermide luteo-olivacea vel olivaceo-f usca ; 

 umbonibus convexis, prominentibus, decorticatis, angulatim 



Fig. \^.—rarrc>isia {P.) facidens (Bens.), YM\pla(;/iosoma (Bens.). 

 (Type.) Nat. size. 



flexuoso-sulcatis, apicibus prominentibus subremotis ; ligamento 

 brevi ; carina umbonali obtusa ; lunula elliptica ; dentibus cardi- 

 nalibus crassiusculis, radiatim eroso-sulcatis, lateralibus sub- 

 elevatis, modice elongatis, obliquis, valva? sinistrae duplicibus, 

 dextra3 simplicibus : margarita colore salmonis tincta. 



Long. 2(j, lat. 39, diam. 18 mm. 

 „ 22, „ 32, „ 15 mm. 



"The anterior cicatrices, as well as the posterior, are sub- 

 confluent, the apical ones situated on the undei-side of the 

 cardinal teeth. The nacre is very iridescent posteriorly. A dark 



