117 



CHAPTER XXIX. 



OF THE MVREX. GENLS XXVI. 



MUREX. 



"Animal a Limax. Shell univalve, spiral, rough, with membranaceous 

 sutures ; aperture ending in a canal, whole, straight, or a little ascend- 

 ing." — Linn. 



iHE essential character of this genus consists in the straight 

 canal or beak that terminates the mouth at that part which 

 is called the base by Linnaeus. 



There is some variation in the form of this canal, as vrell 

 as of the mouth: some shells have a long straight open canal 

 or gutter, as M. cornuius, Spirillus, &c. ; others have it long, 

 but almost closed, as M. Haustellum, &c. ; in some it is not 

 so long, but entirely closed, forming a complete tube, as 

 M. tripterus ; in others short and open, as Morio : sometimes it 

 turns up towards the back of the shell, which Linnaeus calls 

 ascending, as M. Amis, Aluco, &c. : many have no canal pro- 

 jecting beyond the surface of the shell, but appear as if trun- 

 cate, with only a hollow like some of the Buccina, as ilf. Ri- 

 cinns, and most of the fourth division Ecaudati. 



The aperture in some is oval, as Haustellum ; in many it is 

 oblong and somewhat pointed at the ends, as Lotoriuin ; in 

 some it is large, as in Melougena ; in others it is almost linear. 



