194 SUPPLEMENT. 



P. 171. Dentalium bifissum belongs to the Solenoconchia, 

 and is the type of a genus which I have named Dischides ; it 

 is also fossil in the Italian tertiaries, and inhabits the Mediter- 

 ranean, as well as the Gulf of Gascony, the Straits of Gibral- 

 tar, and the sea-bed near Teneriffe ! 



P. 171. T. NAVALIS. E. Arcachon (Lafont)! Trieste 

 (Stossich) ! 



P. 174. T. PEDICELLATA. Arcachon (Fischer)!; Naples 

 (Tiberi and Acton) ! ; Zara, in the woodwork of the bathing- 

 machines, with T. Norvegica (J. G. J.); Algiers ("Weinkauff ) ! 



P. 176. T. MEGOTAKA. Uist, Hebrides (M'Intosh) ! ; Ma- 

 deira (Watson) ! 



P. 181. It does not appear that any of these occasional 

 visitants are alive when they reach our shores, much less that 

 they can thrive and propagate which, indeed, is not desirable. 



P. 181. T. mdlleolus. Arcachon (Fischer)!; Madeira 

 (Watson)! 



P. 182. T. Upinnata. Hayle (Hockin); Faroe I. (Morch). 



P. 184. T. minima. If this be not the Mediterranean 

 species, what is it ? In some specimens the pallet-stalks are 

 very long, and the joints are not spinous at the sides. 



P. 185. SOLENOCONCHIA. I overlooked the Rev. L. Guild- 

 ing's paper in the Transactions of the Linnean Society (xvii., 

 1834) entitled " Observations on Naticina and Dentalium, two 

 genera of Molluscous animals," which shows that he had as- 

 certained the true nature and organization of Dentalium. Its 

 habits, peculiar mode of locomotion, gills, numerous and elon- 

 gated tentacles with their suctorial extremities, vermicular 

 foot, and the position of the anal duct were most accurately 

 described by this excellent observer. The late Professor 

 Costa, in his ' Fauna del regno di Napoli,' gave also some 

 details and elaborate figures of its anatomy, but mistook the 

 tentacles for branchial cirri ; he noticed the occurrence of 

 Foraminifera in its stomach. I would remark that the thread- 

 like and extensile organs by which the Solenoconchia seize 

 their prey are unlike the tentacles of any Gastropod, and their 

 function is quite different : captacula would be a more appro- 



