102 



15. Murex irregularis, spec. nov. Plate vi., fig. 3. 

 Similar to M. Ilamiltonensis, witli eiglit whorls, apex con- 

 siderably smaller, the whorls abruptly truncated medially, the- 

 transverse lamina^ closer together and inconspicuously raised 

 into scales, the varices irregular, three on the last whorl, in- 

 creasing to four or six on the next whorls. The fifth and sixth 

 whorls bicarinate and multicostate. 



Length, 27 ; breadth, 11 ; length of aperture, 7 ; length of 

 canal, 7 ; breadth of aperture, 5. 



Locality. — Lower beds at Muddy Creek. 



Subgenus Eni^^ocAis^TnA. 



SYNOPSIS OF SPECIES. 



Spire whorls subquadrate, conspicuously lirate ; varices- 

 compressed, elevated. 16. M. asteriscus. 



Spire whorls angular, faintly lirate ; varices thick and de- 

 pressed. 17. M. p achy stir us. 



16. Murex asteriscus, spec. nov. Plate ii., fig. 10. 



Shell pyriform, with a low, somewhat trochiform spire, ter- 

 minating in a small blunt mamillate apex of one and a half 

 globose whorls. Whorls six and a half, the anterior ones sub- 

 quadrate with a deeply impressed suture, graduating to flat- 

 sided in the most posterior one. Penultimate whorl bicarin- 

 ated, with a third angulated thread on the anterior slope, 

 faintly ridged in a spiral and transverse direction. 



Last whorl tumid, flattened posteriorly and abruptly attenu- 

 ated anteriorly ; ornamented with five spiral ribs in front of" 

 the shoulder, the interstitial spaces with spiral threads and 

 transverse stride. 



Varices, six on each whorl, obliquely continuous from whorl 

 to whorl, simple, narrow, elevated, crenately-nodulose coninci- 

 dent with the lirse. Aperture large, ovately-obloug ; outer lip 

 lirate within ; columella curved, thickened at its junction with 

 the canal which is shorter than the aperture, nearly straight. 



Length, 27 ; breadth, 19 ; length of aperture, 11 ; of canal,. 

 9 ; breadth of aperture, 7. 



Locality. — Lower beds at Muddy Creek. 



17. Murex pachystirus, spec. nov. Plate ii., fig. 11. 

 Shell resembling M. asteriscus with a higher and flatter spire. 

 "Whorls six and a half, angulated next to the anterior suture ;. 

 striated spirally, and each provided with six broad, depressed 

 varicif orm plications, those of one whorl more or less alter- 

 nating with those of the next, undulose between the varices. 

 Last whorl ornamented with six equidistant spiral ribs, which 



