324 CRETACEOUS PELECYPODA 



Jicie concentrice mimite et confertim striata, umbonibiis parvulis, approximatis ; 

 deutibus cardlnis nmnerosis, fovea triangulari sub apicem divisis. 



Height of shell : its length ... ... ... ... Oo3. 



Thickness „ : „ ... ... ... ... 0-29. 



This species is allied to the recent Yoldla Thraciformis, but is of smaller size 

 and has the striation stronger. It seems to be a very rare shell, as only a single 

 specimen of a left valve exists in our collection. I have, therefore, given an enlarged 

 view of Porbes' original. As to general form the species would be taken for a 

 Neilo, but it has distinctly a small cartilage pit below the umbo and no trace of 

 a ligament. 



Locality. — North of Karapaudy, in a soft coarse sandstone ; Pondicherry. 



Formation. — Arrialoor group. 



2. YoLDiA OBTUSATA, StoUczJca, PI. XVII, Pigs. 7-10. 



Y. testa ovato elongata, tumida, sub-inrnquilaterali, antice sub-rotundata, postice 

 paululum longiore, sub-truncata et p)rope marginem siiperiorem mdistincter sulcata, 

 lunula lata, medio paulo elevata, lateraliter applanata, concentrice confertim striata 

 et nonnullis sulcis j^i'ofundioribus prcedita ; cardine deutibus numerosissimis in utroque 

 latere fovece parvx instructo. 



Height of shell : its length ... ... ... ... 0-66 



Thickness „ : „ ... ... ... ... 059 



Easily distinguished from Y. sub-recurva, PhilL, and other allied species by 

 its more inflated form and very numerous and small hinge-teeth. 



Locality. — Karapaudy, in soft, coarse, whitish sandstone ; not common. A 

 similar and perhaps identical species also occurs in the coarse sandstones near 

 Streeparmatoor. 



Formation. — Arrialoor group . 



3. YoLDiA SCAPHULOIDEA, StoUczka, PI. XVII, Pigs. 11-12. 



Y. testa elongata, siib-tumida, sub-incequilaterali, antice rotundata, postice 

 sub-caudata, sensim attenuata et compiressiuscula, stcb-sulcata, margine areali 

 concavo, area angusta, deplanata, umbonibus tumidulis, actiusculis, approximatis 

 instructa ; superficie concentrice confertim regulariterque striata ; cardine dentibus 

 numerosis pji'csdito. 



Height of shell : its length ... ... ... ... 0'61 



Thickness „ : „ ... ... ... ... 0-35 



This species is very like the Neocomien Y. scaplia, d'Orb., but is distinctly 

 less elongated. It differs from striatula by being more attenuated posteriorly, and 

 from obtusata by being a much more compressed shell. 



Locality. — ComarapoUiam, in soft whitish sandstone ; apparently rare. 



Formation. — Arrialoor group. 



