167 



are clearly distinct ; I feel now pretty confident that wo must consider more 

 than one-half of the species to have become extinct in our seas. This alone, 

 if confirmed by farther and more extended observations, would, I presume, 

 prevent this formation being referred to any period later than the Miocene ; 

 though, as far as I can make out, by the works I have by me, it has always 

 been considered as Pliocene or Pleistocene, (see Hochstetter's "New Zealand," 

 p. 61 — ■" Younger Tertiary Strata," etc.) 



Doubtless some of the species may be extinct here, and alive elsewhere, 

 but I fancy this is improbable. The presence of several of the genera, as 

 Cassidaria, Conus, etc., seems to indicate, if anything, a somewhat warmer 

 climate, but I see no approach to the shells of Port Jackson, in the latitude of 

 the North Cape. 



Of the Chilian shells (I did pick up shells there ages ago), I have little 

 recollection. 



It appears to me, however, that the proportion of extinct species is much 

 less striking than the number of extinct genera. Woodward writes, p. 421, 

 " The shells of the newer tertiaries, are always identical, at least genericcdly, 

 with those of the nearest coasts." But here we have the following genera, none 

 of which, as far as I know, have been found recent. 



Typhis (the Rev. Mr. Taylor's Typhis, was, I think, a Murex), Pyrula, 

 Cassidaria, Conus, Sigaretus, Turritella, Avdcula, Perna, Cuculkea, Limojjsis, 

 Crassatella, Mya, with one of the sub-genera of Natica. 



I shall append a list of all the genera I have determined, and when you 

 come this way I can show you these and other specimens. 



LIST EEEERRED TO. 

 (The extinct species are marked in italics.) 

 Muricidse (14) — Murex, Murex sp. (1), Typhis, Triton 2 sp., Fusus 7 sp., 

 Trojihon, Pyrula. 



Buccinidse (6) — Buccinum, Buccinum 2 sp., Cassidaria, Nassa, Ancillaria. 



Conida? (3) — Conus, Pleurotoma, Mangelia. 



Yolutida^ (5) — Yoluta 2 sp., Marginella, Marginella 2 sp. (?) 



Cyprseidse (1) — Cyprcea. 



Naticida? (4) — Natica 2 sp., Polinices, Globulus, Sigaretus. 



Py ramidellida? ( 1 ) — Chemnitzia. 



Cerithiadse (2) — Cerithium, Struthiolaria 2 sp. 



Turritellida? (2) — Turritella 2 sp. 



Litorinidse (1) — Solarium. 



Turbinida? (l) — Trochus. 



Calyptrseida? (1) — Calyptrrea, Crepidula. 



Dentaliadae (3) — Dentalium, Dentalium 2 sp. 



Tornatellidse ( 1 ) — Tornatella. 



Bullidre (2) — Cylichna 2 sp. 



Phynchonellidse (1 ) — Phynchonella. 



Ostreidse (5) — Placunomia, Lima, Limatula, Pecten 2 sp. 



Aviculida? (3) Pinna, Avicula, Perna. 



Mytilidaa (1)— Modiola. 



Arcade (5) — Area, Cucullsea, Pectunculus, Solenella, Limopsis 2 sp. 



Cardiadse ( 1 ) — Cardium. 



Lucinida? (1) — Lucina. 



Cyprinida? (2) — Crassatella, Venericardia. 



Yenerida? (3) — Yenus 2 sp., Artemis. 



Mactriche (1) — Lutraria. 



Tellinida; (1)— Tellina. 



Myacida? (2) — Mya, Corhula. 



