48 FAUNA OP BALUCHI STliV. 



3. Pamily : CYPBlNrD^. 



Genus : CYPEINA, Lamark. 



Ctprina mazariana, spec. nov. PL XII. fig. 6-6b. 



Dimension!. 



Length 48 mm. 



Height 34 „ 



Thickness 22 „ 



The shell is triangular in shape, equivalve, but inequilateral. The beaks are in- 

 flated but depressed, and situated in the anterior half of the shell. Anterior margin 

 rounded and passing gently into the slightly curved ventral margin, which forms 

 an obtuse angle with the short, apparently slightly convex, posterior margin. The 

 valves are moderately inflated, and slope very gradually in the ventral direction. A 

 strong rounded keel runs from the beak to the angle of the ventral and posterior 

 margin behind which the surface drops nearly vertically. A second more obtuse 

 keel runs from the beak to the point where the posterior and cardinal margins join ; 

 behind this angle the surface is concave, the two valves forming a deeply hollowed 

 ligamental area. Lunula long and broad. Ornamentation only in the shape of 

 striae of growth often raised into strong wrinkles. 



Jjocality and stratigraphical position. — Maz^r Drik, horizon 8. 



'Remarks. — This species exhibits a great resemblance to Cyprina forbesiana 

 from Southern India. But on comparison it will be seen that the two forms are 

 different. Quite apart from the ornamentation of the anterior part of Cyprina 

 Jorbesiana, which consists of sharp and strong concentric ribs, the general shape of 

 the two species differs considerably. Qyprina forbesiana is much longer than it is 

 high, posteriorly elongated, and rather short in front ; in Cyprina mazariana there 

 is not such a great difference between length and height, and the posterior side is 

 rather short, ; the valves are therefore somewhat triangular in shape in Oi/^jrwa 

 wjasarjaraa, while they are transversely elliptical in Cyprina forbesiana ; in the latter 

 species the beaks are much more, anteriorly situated than in the former, where they 

 are more median. 



The next European relation is the well known' Cyprina Ugeriensis, d'Orbigny, 

 but this form is easily distinguished by its more inflated valves, but particularly by 

 the longer ligamental area. 



It also seems that the Baluohistd,n form exhibits a more circular ventral mar- 

 gin, which is only slightly curved in Cyprina Ugeriensis. 



Ctprina dbsbnsis, spec. nov. PI. SII. fig. 7-7b. 



Dimensions. 



Length ............52 mm. 



Height 37 „ 



Thickness 24 » 



The shell is equivalve, transversely elliptical in shape, and rather inequilateral. 

 The anterior side is short and rounded, the posterior side elongated, but somewhat 



