94 



6. Typhis evaricosus, spec. nov. Plate i., lig. 6.* 



Shell acuminately ovate ; whorls six and a half, of which 

 the two and a half apical ones are rounded and smooth ; the 

 rest of the spire whorls are convex, flattened at the suture, 

 beariuof tubulations at the shoulder which are broad, com- 

 pressed, and prolonged backward ; the posterior margin of 

 -each whorls is undulate. Body Avhorl with four tubulations, 

 which are broad at the base, compressed, slightly bent to the 

 left, and adpressed to the spire ; the tubulations are continued 

 •on the anterior portion of the whorl as broad, curved, medially 

 depressed undulations. There are no varices between the 

 tubulations. 



Aperture oval ; peristome continuous ; canal closed, com- 

 pressed, broad, and abruptly tapering to a short hardly re- 

 <3urved point. 



Surface smooth and shining, marked with striae of growth 

 and faint spiral lines, and faintly obliquely ridged on the 

 tubulations. 



Length, 7 ; breadth, 3 ; length of aperture and canal 3. 



Locality. — Lower beds at Muddy Creek. 



T. evaricosus agrees with the recent species T. duplicatus. 

 Sow., and T. arcuatus, Hinds., in having the tubulations bent 

 back, and the varices obliterated by confluence therewith ; from 

 the first, to which it is more allied, it differs by its smaller size 

 and adpressed tubulations. 



Genus Murex. 

 synopsis oe subgeneea. 

 Varices three, wing-like Fteronotus. 



Varices three, foliar Chicoreus. 



Varices more than three 



Canal long, nearly straight ; spire very short. 



Uliinocantlia. 

 Canal short. 



Avarices spinose. Plii/Uonotus. 



Avarices foliated or simple Ocinelra. 



SuBGExrs Pteronotus. 



SYNOPSIS OF SPECIES. 



I. Varices three on each whorl, continuous from whorl to 

 whorl. 



* The figure, which was drawu from a worn specimen, though fairly repre- 

 senting the shape and position of the tubulations. does not show the tubula- 

 tions applied to the spire in the manner exhibited by subsequently acquired 

 examples. 



