GENUS HARP A . 3 



these two genera are inconsiderable; they consist in the ex- 

 tremity of the trunk, which, in the animal of the Harps, is desti- 

 tute of lips bristling with spines, and in the conformation of the 

 stomach, which is less developed than that of the BUCCINUM. 



The fleshy part of this mollusk is very strong, and yery 

 large; its foot is enormous, thick, and extended considerably 

 out of the shell ; it cannot be wholly contained within the aper- 

 ture, before which, by contracting itself, it forms a margin, 

 as has been already pointed out by Born (Musceum C&saris 

 Vindobonensis, pi. 254). 



This author seems to have known the particular circumstance 

 of the rent of the foot. The foot is as if divided into two por- 

 tions. The anterior broader, arcuated, ear-shaped, with a mar- 

 ginal furrow, and joined to the posterior part by a kind of neck. 

 This latter, more extended, is somewhat oval, pointed, and 

 slightly inflated above, without any appearance of operculum. 

 The three authors who have described this animal, point out a 

 singular peculiarity in it : when it is violently disturbed, it breaks 

 off the posterior extremity of its foot, in order to withdraw itself 

 more completely within its shell. It is supposed that this part 

 has the power of reproducing itself after the rupture. 



All the external parts of the animal are strongly colored with 

 spots and plates of a brownish red, intermingled with other yel- 

 lowish spots. The middle portion is frequently crossed by a 

 brown band. 



The respiratory tube is long, rather large, continued to and 

 terminating in a large pulmonary cavity, the use of which is to 

 assist respiration. Upon one side of this cavity are two pecti- 

 nated branchiae, one large, and the other small ; upon the oppo- 

 site side are situated, in female specimens, the rectum and the 

 uterus ; and in the male a deferential canal and a penis. On 

 this same side are fixed, at the upper part of the cavity, the mu- 

 cous follicles, composed of seven or eight transverse plates. 

 The tongue is small, slender, pointed, fleshy, without any trace 

 of a ribbon of horn ; it is contained in an incurved sheath, and 

 rarely protruded from it. The stomach is very narrow, and does 

 not differ in size from the rest of the intestinal canal. The rec- 

 tum is pretty large, terminated by an anus slightly narrowed and 



