TO GEOLOGY. 193 



FAMILY LAMELLIFERJE. 



GENUS TURBINOLIA. (Lamarck.) 



T. Madurii* Plate 6. Fig. 206. 



Description. Turbinolia cuneate, minutely granulate, 

 without ribs or furrows, swollen, furnished with two longi- 

 tudinal tubercles on each side, on the superior part ; base 

 rounded ; star subelliptical ; pores very minute and irregu- 

 larly interspersed among the granules ; lamellae granulate. 

 Diam. .6, Length .8, Breadth .9, of an inch. 



The segment is a magnified view. 



Observations. This very curious species differs in its 

 exterior characters from any other I am acquainted with. 

 It has no longitudinal striae, which all the other known 

 species have. No other described species has longitudinal 

 tubercles like this. The granules are very small and 

 sometimes form together. In several specimens four to 

 eight smaller tubercles, or rather ribs, as they are elon- 

 gated, may be observed on each side, but these are not 

 specifically different. The superior part appears to be 

 very fragile, there not being among a great number a 

 single one entirely perfect in that part. 



* Named after the distinguished geologist, William M'Clure, Presi- 

 dent of the Academy of Natural Sciences of Philadelphia. 

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