376 MOLLUSC A. 



■whorls, render the margin undulated; the inferior whorl is ample 

 and ventricose. Montfort subdivides them into 



DoLiuM, properly so called, where the lower part of the columella 

 is twisted(l), and into 



Perdix, where it is trenchant(2). 



Their animal has a very large foot, widened before; a proboscis 

 longer than its shell, and slender tentacula, on the external side of 

 •which, and near the base, are the eyes; the head has no veil, nor has 

 the foot an operculum. 



Harpa, Lam. 



The Harpse are easily recognized by the projecting, transverse 

 ribs on the whorls; the last of which forms a lip on the margin. 

 The shell is beautiful, and the animal has a very large foot, pointed 

 behind, and widened in its anterior portion, which is distinguished 

 by two deep emarginations. The eyes are on the sides of the tenta- 

 cula, and near their base. It has neither veil nor Operculum;^3). The 



Purpura, Brug. 



Is known by its flattened columella, which is trenchant near the 

 end opposite to the spire, and which, with the external margin, 

 forms a canal there, sunk in the shell, but not salient. The Pur- 

 purae were scattered among the Buccina and the Murices of Lin- 

 nseus. The animal resembles that of a true Buccinum(4). 



The genus Licornp:, Montf., — MoNocEROS,Lam., consists of shells 

 similar to the Purpurae,but in which the external edge of the emar- 

 ginatiou is furnished with a salient spine(5). 



Others, also resembling the Purpurae, in which the columella or 



(1) Buc okarium, List., 985, 44, and Sowerb., Gen. of Shells, No. 29;—^. 

 galea, List. 898, 18;— ^B. doUum, List., 899, 19;— -B. fasciatum, Brug., Mart., Ill, 

 cxviii, 1081; — B.pomum, Id., II, xxxvi, 370, 371. 



(2) Bucc. perdix. List. , 984, 43. 



(3) Buccinum harpa, L., and the other species long confounded with it — List., 

 992, 993, 994; Mart., Ill, cxix; Bucc. costatum, lb. Messrs Ileynaud, Qiioy and 

 Gaymard have observed, that, under certain circumstances, the posterior part of 

 the foot is spontaneously detached. 



(4) Buccinum persicum, List.;, 987, 46,47; — B. patulum. Id., 989, 49;— 5. han- 

 mastoma. Id., 988, 48;— 5. trochlea^ B. lapillus. Id., 965, 18, \%—Murex fucus. 

 Id. 990, 5Q;—Mar. histrix. Martini, III, ci, 974, 975;— Mur. mancinella. List., 956, 

 7, 8, 957, 9—\0;—Mur. hippocastanum. List., 955,996, 990,991. 



(5) Buccinum monodon, Gm., Martini, III, Ixix, 76\\~Bucc. narvul, Brug.;— 5. 

 unicorne. Id. 



I 



