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this and some other speciesof Spirifer, with the internal 
structure manifested, have been found in the Cave near 
Castleton, Derbyshire, by Mr. Mawe, and these have 
enabled me to decide the species of the one I formerly 
had (fig. 1) and to compare Mr. Martin’s own specimen 
of An. trigonalis with those I found perfect enough for 
figureing, see figs. 2 and 3. 
Fig. 4 represents two views of the spiral appendages 
separated, they are generally coated by crystals of Car- 
bonate of Lime ; within they are composed of a somewhat 
fibrous shelly substance. 
R. Brown, Esq. is probably the first person who ob- 
served the spiral cartilage in a Calcedonic cast of another 
species found by him in New Holland, 
