76 MOLLUSCA. 



but not digitated. The foot is proportionably small, and the eyes are 

 supported by lateral pedicles of the tentacula, thicker than the ten- 

 tacula themselves The operculum is horny, long and narrow, and 

 placed on a thin tail *. In the 



Pterocera, Lam. 



The margin, in the adult, is divided into long and slender digita- 

 tions, varying in number, according to the species. The animal is 

 the same as that of the true Strombus f . 



In other Strombi, the sinus of the external margin is contiguous 

 to the canal, forming the Rostellaria, Lam. There is usually a 

 second canal ascending the spire, formed by the external margin 

 and by a continuation of the columella. 



In some of them, the margin is still digitated. Their animal re- 

 sembles that of a Murex, but has only a very small operculum;}:. 



In others, we merely observe a dentated margin. Their canal is 

 long and straight §. 



In some again, that margin is entire ; they are the Hippocrenes. 

 Montf. II 



ORDER VII. 

 TUBULIBRANCHIATA. 



The Tubulibranchiata should be detached from the Pectini- 

 branchiata, with which they are very closely allied, because the shell, 

 which resembles a more or less irregularly shaped tube, only spiral at 

 the commencement, attaches itself to various bodies; they conse- 

 quently are deprived of copulating organs, and fecundate themselves. 

 In the 



Vermetus, Adans., 



We remark a tubular shell whose whorls, at an early age, still form 

 a kind of spire, but then continue on in a tube more or less irregu- 

 larly contorted, or bent like the tubes of a Serpula. This shell usually 

 attaches itself by interlacing with others of the same species, or is 

 partly enveloped by Lithophytes : the animal, having no power of 



* Nearly all the Sti-ombi comprised in the second and third division of Gmelin, 

 observing, that owing to the various degrees of development acquired by the exter- 

 nal margin, there are several repetitions. 



t Strombus lambis, Rondel., 79; — Martini, III, Ixxxvi, 855; — Str. chiragra, List,, 

 870;— S<r. millepeda, List., 868, 869 ;— S/r. scorpius, List., 867. 



X Strombus pes pelecani, L., List., 865, 866. 



§ Stro7nbus/usus, L., List., 854, U, 12, 916, 9. 



II Strombus amplus, Brander., Foss., Hant., VI, 76, or Rostellavia macroplera. 

 Lam.; Str.JissttreUa,'Laim., Encycl. Method., p. 411, 3, «, b, which is not that of 

 Martini, IV, clviii, HfS, 1499, &c. 



