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Supplement to a Notice of Fossil Crustacea. By Jer. 

 Van Rensselaer, M. D. Read January 24, 1825. 



In a short notice which I had the honour to read to the 

 Lyceum a few weeks ago, mention was made, in a note, of 

 part of a fossil crab in the possession of Major Delafield, that 

 could not be found. I have now the satisfaction to mention, 

 that it has been for more than eight months, in the Cabinet of 

 the Lyceum. 



It is the thumb of a large crab, much larger than any simi- 

 lar part of this animal that I remember to have seen fossil. Its 

 shape is an incurvated cone, having on the inner margin a row 

 of tubercles. This specimen diners from any that I have seen 

 described, and was found in the vicinity of Yorktown, Virginia, 

 imbedded in a conglomerate, similar to the matrix of the va- 

 luable fossil shells lately presented to our Cabinet. Among 

 these we find many of the beautiful varieties characterising 

 the tertiary formations of Europe. 



Descriptions of new American species of the Genera 

 Buprestis, Trachys, and Elater. By Thomas Say. 



Read January 17, 1825. 



Buprestis. 

 1. B. transversa. Cupreous or blackish; elytra with striae 

 of punctures ; a glabrous line between the eyes. 



Description. Body varying in colour, from a dull cupreous 

 to brownish black : head with large, confluent punctures, 

 and a distinct elevated line extending transversely between 

 the e}'es : eyes distant : thorax with large confluent punc- 



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