94 LESSON XI. 



tubercles, or varices ; aperture oval ending in a 

 straight or slightly ascending canal. Some of 

 the species are remarkable for the great lengt 

 of the beak. 



OBSERVATIONS ON THE SHELL AND ITS 

 INHABITANT. 



The very great variety which occurs in the 

 shells of this genus has caused them to be ar- 

 ranged under several divisions ; but the mark by 

 which a Murex, according to the Linnaean de- 

 finition, may be easily recognised, is the oval 

 shape of the mouth ; for this is preserved even 

 when the aperture is terminated by a beak, as 

 instead of gradually contracting, it abruptly opens 

 into a canal. Besides this regularity in the out- 

 line of the aperture, the beak neither inclines to 

 the right nor to the left. 



The Murices are in general of an irregular 

 form, arising from their surfaces being covered 

 either with spines, tubercles, varices, or folia- 

 tions ; and from the rock- like and rugged appear- 

 ance thus occasioned they derive their designa- 

 tion. Many of the shells of this genus are re- 

 markable for the singular extension of their 

 beak. Those of one division are elegantly 

 adorned with foliated expansions ; they were 

 anciently called Purpurae, because the animals 

 inhabiting them yielded the famous purple dye. 



Many of the Murices are distinguished by 

 their thick protuberent rounded varices. These 

 shells have been divided into different genera 



