112 



Bulletin 39 



Height 265, diameter 136, aperture 158, last whorl 195 

 mm. 



This very remarkable species is an extreme development of 

 the X. scolynius stock in which the upper portion of the whorl 

 becomes a wide, deep, excavated sutural zone. Above this ex- 

 cavated zone, project the high, rounded or appressed ribs and the 

 carinate edge of the whorls. X. scolymus Gmelin, a recent spec- 

 ice found plentifully along the north Panama coast, has the 

 whorls simply shouldered, often merely rounded. 



The Santo Domingan Miocene contains X. validus Sowerby, 

 which has been identified by some with scolymus. In validus, the 

 ribs are more numerous (about 10) and are sharper and more tub- 

 ercular in form. 



Gatun Stage: Baiiana River. 



Genus IVIEL0N6ENA Schumacher 



Melongena consors Sowerby Plate 9, figure I 



Pyrula consors Sowerby, 1849, Quart. Journ. Geol. Soc. London, voL6, 

 p. 49. 



Melongena melongena Gabb, 1873, Trans. Amer. PhiL Soc, voL 15, P* 



205. Not of Linnseus. 

 Pyrula melongena Guppy, 1874, GeoL Mag., voL 11, p. 438. 

 Pyrula melongena Guppy, 1876, Quart. Journ. GeoL Soc. London, voL 



32, p. 523. 



Melongena consors Dall, 1900, Trans, Wagner Free Inst. Sci,, voL 3, pt 

 I, p. 121. 



Melongena consors Maury, BulL Amer. PaL, voL 5, p. 249, pL 14, 

 fig. 5- 



The Melonge^ia consors is not a common fossil in Costa Rica. 

 It is closely related to the recent M. corona Gmelin of the West 

 Indies, the fossils shells differing mostly in having a longer spire 

 and somewhat different sculpture above. 



The Costa Rican examples are exactly like Miocene speci- 

 mens from Santo Doingo. As a fossil it occurs in the Miocene 

 of Jamaica, Santo Domingo and Venezuela. 



