MONOGRAPH OF THE GENUS 

 ANCILLARIA, Lamh. 



Char. Gen. Testa polita, ovata vel oblonga, ad basin balteo in- 

 crassato marginata ; supra balteum sutura nonnunquam celata, 

 plerumque ad terminuiii dentifera cincta ; spira pyratnidali, su- 

 tura tegmine calloso, polito celata ; columella varice calloso, 

 plerumque striato, ad basin terminante; apertura magna, antice 

 effusa, plerumque unidentata, ad basin emarginata ; operculo 

 corneo, concentrico, subovali. 



Although Lamarck first published this genus under the name 

 of " Ancilla," I cannot admit the justice or convenience of re- 

 fusing to adopt the alteration which he subsequently made. That 

 alteration appeared in all his more matured works, and has been 

 almost universally adopted. The species have increased in num- 

 ber from four described in the ' Animaux sans Vertebres/ to 

 forty-four contained in the present monograph. This includes 

 " Buccinum glabralum " of Linuseus, which is unfortunately 

 placed at the head of Lamarck's genus " Eburna," but which 

 has no connection with the other species enumerated under that 

 title. It is admitted here, with two allied species, by general 

 consent, the most advanced of modern conchologists making 

 only a subgenus of the group. The Anclllaria are polished, 

 olive-shaped shells, with the spiral suture covered by a coating of 

 enamel, having an oblique, thickened belt at the base, which is 

 sometimes double ; above this belt is a suture, generally ending 

 in a tooth near the base of the outer lip, but which is some- 

 times covered and hidden by enamel, and a tortuous triangular 

 varis. at the lower part of the columella. The operculum is 

 horny, oval, and concentric. The species may be thus arranged : 

 — Section I., Sp. 1 to 21, in which the spire-covering enamel 

 is continued downwards as far as, and sometimes over, the basal 

 suture. Section II., Sp. 22 to 41, in which the said enamel 



VOL. III. F 



