332 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb. 27, 



Blue Clay of Wanganuij in the North Island. 



In my former Memoir on the Fossil Birds of New Zealand, a bed 

 of clay abounding in marine shells was described as underlying the 

 bone-deposit *. A few specimens from this locality were sent in the 

 present collection ; they are in the same condition as the shells of 

 Onekakara, and the stratum whence they were obtained is evidently 

 of the same age ; they are all of species existing in the South Pacific 

 Ocean : 



Fusus nodosuSy Quoy. Venericardia Quoyii, Lamarck. 



Murex Zealandicus, Quoy. Pecten asjperrimus, Lamarck. 



Venus mesodesma, Gray. 



Infusorial Earth of Taranaki. 



.Hong the shores of the North Island, and especially within a short 

 distance of New Plymouth, there are extensive low mounds or hills 

 of a siliceo-calcareous sand, of a light fawn colour, and which in 

 some places is aggregated into concretionary friable masses. This 

 deposit is in a great measure composed of the siliceous shields or 

 frustules of Diatomacece, those vegetable structures which Ehrenberg 

 considered of animal origin, and described as Infusoria. From the 

 many forms similar to those so universally present in marine and 

 brackish water deposits, I have selected a few which are delineated 

 in Pl. XXIX., to convey an idea of the organic composition of this 

 earth. 



Stauroneis Zealandica, nov. spec. : Pl. XXIX. figs. 4, 5. This beau- 

 tiful organism is very like a species from the " Little Falls," State of 

 New York, but differs in the form of the shield, which is subangular 

 in the middle, and in the central bar or cross ; I have therefore given 

 it a specific name. 



Surrirella : Pl. XXIX. figs. 6, 7. "Resembles S. hifrons, Ehrenb." 

 — Mr. R. Jones. 



Navicula lihrile^ Ehrenb. 



Vinnularia ; Pl. XXIX. fig. 8. Mr. Topping informs me that the 

 same form occurs in the Thames at Tilbury Fort. 



Cocconema. " Resembling C. cymbiforme, Ehrenb." — Mr. R. Jones. 



Actinocyclus '. Pl. XXIX. figs. 9, 10. 



Bacillaria. Polycystina '. Pl. XXIX. fig. 11. 



Eunotia ocellata, Ehrenb. 



Pyxidicula or Posodira : Pl. XXIX. fig. 10. 



Coscinodiscus. 



Mr. Williamson of Manchester informs me, that in addition to the 

 bodies I have detected, he has obtained from the earth I transmitted 

 to him, PolycystinecB apparently identical with species that are 

 abundant in the well-known infusorial earth of Barbadoes ; and disks 

 of Meloseiraf. 



* See Quarterly Journ. Geol. Soc. 1848, vol. iv. p. 239. 



t For the most beautiful preparations of these infusorial earths, and especially 

 for a selection of the most delicate organisms mounted separately, I am indebted 

 to Mr. C. Poulton, of Southern Hill, Reading, whose skill in this department of 



