MUIIEX. 33 



species is easily known by the roundly curved endive-like 

 fronds. 



149. saxicola, f. 152, Broderi'p. — Testa M. endivice 

 similis, sed anfractibus conspicue angulatis, varicibus 

 plerumque magis frequentibus. — I cannot help thinking the 

 decided angularity of M. saxicola is sufficient to distinguish 

 this shell from M. endivia. 



150. saxatilis, f. 177, Linnceus. — Testa magna, subtri- 

 gona, inflata, subrosacea, fulvo fasciata, sexfariam varicosa, 

 scabroso striata ; varicibus ramoso-frondosis, frondibus extan- 

 tibus foliatis, apertura lata, subpyriformi, rubro trifasciata ; 

 canali lato, curvo, late aperto. — The aperture is wide and 

 continues widely open down the curved canal. The early 

 whorls of this species have the fronds very little developed, 

 and we think that M. hoplitus, Fischer, is probably described 

 from a specimen of this species, in which the later varices 

 are not formed. This opinion is formed upon observation of 

 the yotmger portion of a mature M. saxatilis. 



151. radix, f. 170, Qmdvru — Testa magna, globosa, alba, 

 inter varices lsevis ; varicibus ad decenis inter frondes sub- 

 planulatis, frondibus nigris, numerosis, dentato foliatis, 

 crispatim recurvis ; apertura magna alba, canali brevi, 

 incurvo. — The figure represents the ordinary form, and will 

 show the difference between it and M. nigritus, which latter 

 I think there is some reason to adopt. 



152. nigritus, f. 169, Phttvppi. — Testa M. radici simi- 

 lima, frondibus haud tantum dentato-foliaceis, haud crispatim 

 recurvis, canali magis oblique elongato. — The fronds are 

 staffer and straighter than those of M. radix. The proposed 

 third species, M. ambiguus, must be, I think, included with 

 the old species. Then the species will stand thus —M. radix 

 including M. ambiguus, with fronds leafy and dentated, 

 much curled backwards; M. nigritus with fronds plain. 



153. prixceps, f. 175, 176, Broderip. — Testa turbinata 

 crassa lsevis alba, castaneo pone frondes fasciata ; varicibus 

 ad septenis, frondosis ; frondibus erectis ad latera laqueato- 

 dentatis.— It is scarcely a matter of doubt to me that the 

 .1/. nitidus of Broderip is the young of this species. But I 

 have seen many young shells of M. radix that it would be 

 difficult to distinguish from M. prmceps. 



154. brassica, f. 166, Lamarck. — Testa magna globosa, 



F 



