SECTION IV. 



EOCENE GASTEROPODA FKOM THE UPPEB LAYER OF THE UPPER 



MARL BED OF NEW JERSEY. 



Class GASTEEOPODA. 



Subclass PROSOBRANCHIATA. 



Order PECTINIBRANCHIATA. 



MURICID^. 



Genus MUREX Linnseus. 



MuEEX (Pteronotus) l^vavaeicosus, n. sp. 



Plate XXIV, Figs. 1, 3. 



Shell small, ovate, spire elevated, number of volutions unkown, apical 

 angle about 45°. Volutions subglobular between the deeply impressed 

 sutures, the body whorl appearing globular when considered alone. Aper- 

 ture semicircular, beak long, strongly curved and very slender. Volutions 

 crossed by low rounded varices, which in the cast readily slough from the 

 surface, showing that the inner layers of the shell were built up independ- 

 ently of the exterior form, as the shell was continued beyond the line of the 

 varix; lip reflected only in the degree of a varix. Shell marked by fine 

 spiral lines, which are more distinctly indicated on the lower side of the 

 whorl than above; also by very fine transverse lines indicating growth. 



Only a single individual of this species has been observed, and that 

 imperfect above the middle of the second volution. The specimen has been 

 studied by Mr. Conrad in past years, and marked by him as being nearly 

 related to Fusus rugosus Lamarck, as figured by Sowerby. The form of the 

 varices, however, and their condition of preservation show that they were 

 not formed as are those of Fusus, Fasciolaria, and allied genera, but like those 

 of the true Murex. The species is readily distinguished from any known 

 form in our American Eocene, and need not be mistaken, 



190 



