11 



The Nautilus. 



Vol.. XIV. AUGUST, 1900. No. 4. 



A NEW MUREX FROM CALIFORNIA. 



BY WM. H. DALL. 



Murex petri Dull, n. sp. 



Shell solid, when perfect with an acute produced apex of four or 

 five whorls, followed by four ordinary whorls ; nepionie shell with 

 convex shouldered whorls with up to six rounded varices, spirally 

 sculptured with rather prominent threads ; color of the shell purplish- 

 brown more, or less minutely mottled or articulated with paler spots; 

 surface with obsolete flattish spiral threads stronger on the backs of 

 the varices, and, when perfect, also showing very minute spiral stria- 

 tion;' whorls between the varices with a single not very prominent 

 knob ; varices flattish, with five or six projecting points or digita- 

 tions separated by shallow emarginations and slightly excavated on 

 the forward face ; these projections are not recurved ; anterior face of 

 the varices covered with profuse crinkled imbricating lamellae; a 

 marked sulcus between the anterior digitation and the canal ; aper- 

 rure ovate, thickened with a projecting yellowish margin without 

 any dentiform process; the interior shows about six nodular denticles 

 on the anterior two-thirds of the outer lip ; canal closed, rather long, 

 sharply curved to the right; Ion. of shell 65, lat. 32 ; of aperture Ion. 

 15.6, lat. 11.5 mm. 



Habitat, San Pedro, in rather deep water. Mr. and Mrs. Old- 

 royd. 



This shell belongs to a group of Murices which is exceptionally 

 developed on the Pacific coast; having three varices and sometimes 

 a basal tooth projecting from the margin of the aperture. Those 



