89 



•streamlet, and his sluggish thought caught no new inspira- 

 tion from the hum of the insect's wing. Having, then, no 

 ability* to add to the knowledge or happiness of others by 

 his own observations, he could but thank his friends that 

 they had kindly given him a place of quietude, where his 

 privilege would be more to hear than to impart imformation. 



Eev. S. Barden, of Marblehead, spoke a few minutes on 

 .geological matters. He had been to the Serpentine Ledge 

 at the Center, but with small success. The serpentine here 

 is not ornamental in its appearance, not like the precious 

 serpentine of Newbury. It has a dull grey color and con- 

 tains a large share of magnesia. Formerly it was quarried 

 for the manufacture of Epsom Salts. An excavation is seen 

 in the northerly part of the town, where some deluded peo- 

 ple at one time dug for copper. A considerable sum was 

 spent, but nothing found save a very little copper and 

 -micaceous oxide of iron. 



F. W. Putnam, of Salem, having come late, was provid- 

 ed with very little on which to speak. A large mud turtle 

 from a pond near by, was pronounced to be a specimen of 

 the lower order of turtles. These are very voracious, and 

 will even attack a dog when in the water. A rare turtle 

 QEmps Blandingii) had been lately given to the Institute 

 by Mr. Addison Flint of North Reading. It was found in 

 that town and is wholly terrestrial in its habits ; living in the 

 woods, but never in the water. A hinge across the under 

 shell allows the creature to close the front part of his cover- 

 ing and thus protect the head and forefeet; not like the 

 Box Turtle which can close up the whole. According to 

 Agassiz' new classification, this is the only true Emjjs found 

 in North America. One or two snakes and beetles were 

 also spoken of. 



Some remarks on the habits of the Gall Fly and Aphis 



ESSEX INST. PROCEED. VOL. iii. 12. 



