41 



shell-worms, the animal, like them, is of worm-like configuration, and red- 

 blooded. 



The Dentalium shells are mostly white, but there are some brilliant ex- 

 ceptions from the Eastern Seas in D. elephantinum, aprinum, and formosum. 

 The last, collected by Sir Edward Belcher outside a coral reef, near the 

 city of Sooloo, at a depth of sixteen to twenty fathoms, is especially beau- 

 tiful in colour. It is of large fluted growth, richly variegated with rose 

 and olive-green. 



We have two Bentalia in the British Seas, one D. entails, a northern 

 species, the other, D. Tarentinum, a southern species passing into the 

 Mediterranean. 



1. abbreviatum, Desk. 



2. acuminatum, id. 



3. anibiguum, Chemn. 



4. aprinum, Linn. 



5. arcuatum, id. 



6. bicarinatum, Desk. 



7. dentalis, Linn. 



8. eburneum, id. 



9. elephantinum, id. 



10. ensiforme, Chemn. 



11. entalis, Linn. 



12. fissura, Lam. 



Species. 



13. formosum, Ad. 8f R. 



14. Indicum, Chemn. 



15. inversum, Desli. 



16. lacteum, id. 



17. Lessoni, id. 



18. longitrorsum, Reeve. 



19. nebulosum, Linn. 



20. novem-costatum, Lam. 



21. octogonum, id. 



22. perpusillurn, Sow. 



23. politum, Linn. 



24. pseudo-sexagonum, De. 



25. quadrangulare, Sow. 



26. rubescens, Desh. 



27. sectum, id. 



28. splendidum, Sow. 



29. strangulatum, Desk. 



30. striatum, Lam. 



31. subulatum, Desh. 



32. tesseragonum, Sow. 



33. translucidum, Desh. 



34. variabile, id. 



Figure. 



Dentalium elephantinum. PI. 25. Eig. 148. Shell of an exotic fluted 

 species, the largest of the genus, showing that it is open at the apex, 

 as well as at the base.* 



* Since the publication, in 1852, of the Family Ti/rhinacea, attention has been given to a 

 group of minute mollusks, the Cacidce, with tooth-like shells, classed hitherto under Deutalii<m, 

 but shown, through the anatomical researches of Mr. Clark, to have the nearest relationship with 

 Turritella. Prior to the elucidation, by Forbes and Hauley, of the two British species of 

 Caaim, embodying the results of Mr. Clark's dissection, the phenomenon of an unconvoluted 

 Gastropod, without any indication of the spiral which commences in Vermetus, was a kind of zoolo- 

 gical puzzle to naturalists ; one referred it to the Cephalopods, another to the Petropods, and 

 another to the Aunelides. Among the shells from Mazatlan, described by Mr. Philip Carpen- 

 ter, and deposited in the British Museum, a great many Geeca were found, and in a monograph 

 of the genus published in the ' Proceedings of the Zoological Society ' for 1858, he gives cha- 

 racters of as many as forty-three species. 



VOL. II. G 



