11-5 



SIGARETUS, Lamarck. 

 Gen. Char. Shell imivalved, internal, ear 

 shaped, suborbicular ; aperture dilated, en- 

 tire, rounded, oblong, margin divided, inner 

 lip thin; columella spirally curved. 



A SMALL imperfect almost immersed spire, and a lar^e 

 expanded aperture, are common to Stomatella, Hal iotis, 

 and several other genera, from which Sigaretus is dis- 

 tinguished by the form of its thin inner lip applied close 

 upon the spire, leaving a more or less conspicuous um- 

 bilicus in a slender columella, that is so united to the 

 thick edge of the Hp as to appear a continuation of it; 

 a considerable portion of the spire is also visible within 

 the aperture. The surface is often striated or reticu- 

 lated, but has a smooth aspect indicative of its being 

 covered by the animal. Only one fossil species appears 

 to be known, while there are several recent ones, 



SIGARETUS canaliculatiis. 

 TAB. CCCLXXXIV. 

 Spec. Char. Obovate, convex, longitudinally 

 striated; spire pointed, its turns distinguish- 

 ed by a canal ; umbilicus large. 

 Strongly resembling S. concavus of Lamarck, but 

 much smaller, and distinguished besides by its umbili- 

 cus. The stiae upon its surface are elevated, often un- 

 dulated, and even decussated by the lines of growth : 

 it is small and pointed. 



