60 



Genus 3. ANCILLARIA, Bruguiere. 



Animal ; disc ohlong, bifurcated beJdnd, triangularly lohed in front, 

 partiallg reflected over the shell, under surf ace furnished beneath 

 the head with an orifice ; head and tentacles small, with a 

 cylindrical trunk ; respiratory siphon rather prominent. 



Shell ; oblong, cylindrical, widely emarginated at the base ; spire 

 rather short, suture obtuse ; columella obliquely grooved, some- 

 times umbilicated, slightly twisted ; operculum small, horny. 



The Anc'illar'm are a hmited group of mollusks allied to the Olives, yet 

 possessing characters very much opposed to those recorded in that pecuhar 

 genus. According to M. Quo/s figure of the A. albisulcata, the shell is 

 partially imbedded in the substance of the disc, somewhat after the manner 

 of Natica, the middle portion of it being reflected over the shell, not the 

 outer edge as in the Ohve. There is, moreover, no filamentary cord passing 

 from the extremity of the mantle around the spire ; the spire of Ancillaria 

 being distinguished, on the contrary, by a caUous deposit of enamel, a 

 condition the very reverse of that indicated by the deeply excavated groove 

 in the Olive. The hinder extremity of the disc is peculiarly bifurcated ; 

 the front exhibits a similar lobed appearance, and the head and tentacles 

 are small, concealed within the fold of the disc, probably from the animal's 

 habit of burrowing in the sand. 



The shell of Ancillaria differs equally in its lesser detail from that of the 

 Ohve ; it exhibits no pattern or design, and is mainly characterized by an 

 uniform bright golden yellow, passing into a bright cinnamon red. 



The rarest species are from New Holland. 



1. albifasciata, Sicains. 



2. albisulcata, Sow. 



3. aperta, id. 



4. australis, id. 



5. Candida, Lam. 



6. castanea. Sow. 



7. cingulata, id. 



8. cinnamomea, Lam. 



Species 



9. eburnea, Deshayes. 



10. effusa, Swaitison. 



11. exigua. Sow. 



12. fulva, Swainson. 



13. glabrata, id. 



14. mamillata, Hinds. 



15. marginata, Lam. 



16. Mauritiana, Sow. 



17. mucronata. Sow. 

 IS. nivea, Swainson. 



19. oblonga. Sow. 



20. obtusa, Swainson. 



21. rubiginosa, id. 



22. Tankervillii, id. 



23. ventricosa, Lam. 



Ancillaria Mauritiana. 

 white twisted columella. 



Figure. 

 Plate 4. rig. 21. 



Sho\\ing the aperture and 



