NEW FOSSIL AVICUIA. 



163 



Fig. 27, #, which is exceedingly minute, is accompanied 

 with three magnified views ; and Jig, 27, b, with the same. 



I was induced to have both specimens represented, as there 

 are some slight differences between them, which, unless de- 

 pending upon particular periods of growth, may be considered 

 sufficient to constitute them different species or varieties. 



The locality whence I obtained my specimens is the tun- 

 nel of the London and Birmingham rail-road, near Chalk farm. 

 Although I have examined several hundreds from this place, 

 I have only found about eight or nine with the Rotalia at- 

 tached. 1 have had in my possession at different times some 

 thousand specimens of Vermetus Bognoriensis, from High- 

 gate, Bognor, and Sheppey, but I have never before noticed 

 any minute shell or coral attached to them. 



It was at first my intention to have given a specific name ; 

 the present fossil however appears so closely to resemble a 

 species found at Grignon, that I have thought it better not to 

 do so. 



Highgate, March 12th, 1839. 



Art. IV. — Description of a new fossil Avdcula,/rom the Lias Shale 

 of Somersetshire. By Samuel Stutchbury, Esq., Curator to 

 the Bristol Philosophical Institution, &c. 



^; 28 



"Avicula longicostata, Stutchb. 



