392 On the Nomenclature of the Foraminifera. 



merhouse, Thrisliiigton Gap, Running Waters, Moorsley, 

 Walworth and Limekiln Banks, south of Leg's Cross. 



In Yorkshire it is very abundant, occurring, with the Milio- 

 loid variety, in myriads, in the dark-grey limestone of Noster- 

 ficld, and in a similar limestone at Chapel Houses, — also at 

 Gybdykes, near Mashani, Thornton Watlass, Linderick, and 

 Hampole. 



In Ireland it has been found by Prof. W. King at Tully- 

 connel Hill, near Artrea, co. Tyrone. 



In Germany it is very common in the Lower Zechstein of 

 Corbusen, near Ronneburg, and at other places in the vicinity 

 of Gera, at Moderwitz (near Neustadt) on the Orla, at Kams- 

 dorf and Saalfeld, and in the Wetterau (' Dyas,' p. 40). It is 

 found also in the " grauer Mergel-Zechstein," overlying the 

 Zechstein at Gera (King, Journ. Geol. Soc. Dublin, 1856). 



The discoidal or Sjnrillma-like form {Tr. incerta) is found 

 in Durham in "Shell-limestone" at Tunstall Hill, and in 

 " Lower Limestone " at Langton, Thrislington Gap, Walworth, 

 and Limekiln Banks, south of Leg's Cross. 



The Nosterfield limestone, when cut and polished, shows 

 instructive sections, the matrix being almost black, while the 

 shell-substance is white. This rock is similar to the black 

 limestone of Gera and Hanau. 



This little fossil is always associated with other fossils, such 

 as Producta horrida^ Oervilia antiqua^ and Ichthyorachis an- 

 ceps^ often with other Rhizopods, and as often with an obscure 

 plant-like fossil which has been named Chondrus virgatus. 

 It is always free (not attached or parasitic) ; and we do not 

 see any reason to follow Dr. Geinitz* in associating the fixed 

 vermiform fossil ( Vermilia ohscura^ King) with Trochammina 

 pusilla. 



EXPLANATION OF PLATE XIII. 



Fig. 1. Trochammina incerta. From Langton, co. Dui-ham. Magnified 



30 diameters. 

 Figs. 2, 3. Tr. pusilla, subdiscoidal forms. Sunderland. Magn. 15 diams. 

 Figs. 4, 5, G. Tr. jnisilln, ordinary forms. Sunderland. Magn. 15 diams. 

 Figs. 7, 8. Tr. gordialis. Tunstall Hill, Sunderland. Magn. LO diams. 

 Figs. 9-14. Tr. milioJoides, various forms. Sunderland. Magn. 10 diams. 

 Fig. 15. Tr. pusilla, section. Nosterfield. Magn. 15 diams. 



* ' Dyas,' p. 39. In the < N. Jalirbuch &c.' for 18G4, p. G67, Hen- Bolsche 

 also noticed a serpentine form, parasitic on shells &c., and intimated that 

 il and King's V. ohscura may be the same as, or varieties of, the coiled 

 i'orm. 



