238 



STRUTHIOLARIA. 



MA 



n MUREX STRAMINEUS. Linn. 



Sowerbys Genera, No. 1, plate 3. 



This genus in some respects resembles those of Buc- 

 cinum and Murex, with which Linnaeus had blend- 

 ed it, but, in addition to these shells not having any 

 notch at the base of the canal, they have a thickened 

 marginal lip on the right side, which never occurs in 

 either of the above genera. Shell oval, spire elevat- 

 ed; aperture oval, sinuous or winding, terminated at 

 the base by a very short canal, straight and without 

 a notch; left side of the aperture callous and repand- 

 ed, right side with a thickened varix or outward lip, 

 waved and continued to the base. These shells are 

 marine, but the mollusca inhabiting them may be pre 

 sumed often to wander on the shore in search of food, 

 and from the necessity of frequently moving in and out 

 of its shell, produces the singular callosities at the two 

 edges of the aperture. Lamarck does not mention that 

 the whorls of these shells are angular towards their 

 upper side, more or less nodulous; and in some ex- 

 amples a groove or canal separates each whorl from 

 the previous evolution : the spire is obtuse, and shorter 

 than the body whorls. Sowerby observes that the 



