162 UNION IDJE. 



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

 postice superne sensim descendente, demum obtusa, margine 

 ventral! convexiusculo, postice vix emarginato ; disco laeviusculo, 

 concentrice leviter striatulo, antice obsolete radiato-striato, versus 

 marginem ventralem et posteriorem plicato ; epidermide olivaceo- 

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

 apicibus prominentibus obtusis, remotiusculis ; lunula elongato- 

 elliptica ; ligamento brevi ; dentibus cardinalibus crassioribus, 

 radiatim eroso - suleatis, lateralibus obliquis, utriusque valvae 

 duplicibus, subflexuosis ; margarita albida, iridescente. 



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



Anterior cicatrices subconfluent, posterior entirely so, apical 

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



Hob. Gunguu Biver, near Moradabad, Eohilkhund. Specimens 

 in the Indian Museum from Arrah. 



A very distinct cuneiform variety. 



Var. plagiosoma (Benson}. 



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

 Unio favidens, var. plagiosoma, H. & T., 0. I. 1876, p. 6, pi. 11, 

 fig. 3. 



Original description : Testa transverse trigono-ovata, ina3qui- 

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

 convexe declivi, demum obtusa, margine ventral! convexiusculo ; 

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

 umbouibus convexis, prominentibus, decorticatis, angulatim 



Fig. l4.Parrei/sia (P.)faridens(Bens.), var.plagiosoma (Bens.). 

 (Type.) Nat. size. 



flexuoso-sulcatis, apicibus prominentibus subremotis ; ligamento 

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

 nalibus crassiusculis, radiatim eroso-sulcatis, lateralibus sub- 

 elevatis, inodice elougatis, obliquis, valvae sinistra? duplicibus, 

 dextra3 simplicibus : margarita colore salinonis tincta. 



Long. 26, 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 underside of the 

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



