MUREX. 375 



sometimes very delicately and closely sqnamiferous. The 

 spire is composed of about six or six and a half volutions, 

 which are of rather fast longitudinal increase, and are 

 strongly defined by a simple but profoundly impressed 

 suture ; they are rather shelving and flattened or even sub- 

 retuse above, and somewhat ventricose below, of moderate 

 height in the more elongated examples, and rather short in 

 the more stunted forms. Tn the ordinary-sized examples 

 about four-sevenths of the total length is filled by the body, 

 but as the spire is produced in the larger and more aged 

 individuals (and these are rarely taken with the mol- 

 lusk tenanting them) the usual proportion is reduced 

 to one half; it is only moderately ventricose above, and 

 rather narrowly peaked below, the attenuation or basal 

 declination commencing rather early and being tolerably 

 couA'^ex. The aperture barely fills one half of the total 

 length, is of an oval-oblong figure above, and terminates 

 below in a tolerably straight and rather long canal, that is 

 often partially closed over above. It is sometimes white, 

 sometimes liver-coloiired, sometimes dirty violet or lilac, 

 and is greatly contracted in the more mature specimens by 

 the solidification of an outer lip, that is guarded inter- 

 nally by from five to seven dentiform tubercles, which 

 vary as to size, sharpness, and approximation in diiferent 

 individuals. The lip, however, is levelled to a tolerably 

 sharp edge, is unarmed externally, has but little promi- 

 nence, and is moderately arcuated. The pillar lip is 

 unsculptured, rather broad, not much incurved, and con- 

 siderably flattened. There is no perforation. The average 

 of size may be stated at half an inch for the length, and a 

 fifth of an inch for the breadth, but here and there a dead 

 individual is obtained that is at least half as large again 

 as those taken alive. 



