64 



Lamarck describes only three species of this genus as found fossil in 

 the neighbourhood of Paris : R. macroptera, R. columbaria, R.fissurella. 



XXX. Murex. An ovate or oblong univalve, with a channeled base 

 and varicosely tumid ; rough, spinous, or fringed longitudinal and pro- 

 jecting sutures. 



By confining the murices to the shells thus characterized, shells are 

 excluded, with which Bruguiere and Lamarck have formed the genera 

 cerithium, fusus, pyrula, pleurotoma, and fasciolaria. In the murices, the 

 canal, neither suddenly truncated nor abruptly turned back, the colu- 

 mella with no fold, and the left lip of the opening always more or less 

 apparent, always determine the genus. 



Murex tripterus, ofBrander, Born, and Lamarck, is found frequently 

 fossil in Hampshire, and at Grignon, in France; Brander, Foss. PL in. 

 Fig. 79 and 80. Lamarck informs us, that its recent analogue exists in 

 the sea, in the neighbourhood of Batavia. 



M. Contabulatus, Lam. is doubtless a variety of the preceding species. 

 M. tricarinatus, Lam. M. asper, Brand. Fossil hant. Fig. 77, 78, is very 

 remarkable for the spinous projections proceeding from its frondose 

 ridges. 



The shell, Plate V. Fig. 16, is rather a rare shell in the Essex cliff. 

 It is fusiform. The turns of its spire, which are generally six, are thinly 

 set with not very prominent rugae, which, with faint transverse striae, are 

 also observable on the body of the shell ; the opening is smooth on each 

 side, and the canal is rather patent. The rugae, continued to the body 

 of the shell, induce me to term this shell Murex rugosus. 



A fossil murex is much more frequently found in this cliff, which 

 seems to agree exactly with M. comeus, Linn, as figured by Lister, 

 Anim. Angl. t. 3, /. 4, who says it is found, but rarely, 'on the Scarbo- 

 rough coast. 



The shell represented Plate V. Fig. 22, is a shell from the same cliff, 

 of very curious structure; it appears to be M. Erinaceus, Linn. Its 

 specific characters are,* an oblong ovate form ; the spine, formed by five 



