Hyatt. 92 [January 18, 



round-topped hills, which continue until they abut against, or change 

 into, the flesh-colored syenite that lies in contact with the Lynn por- 

 phyries. To the east of this a great thickness of a very remarkable 

 granitic rock had been observed, which presents in various localities 

 a gneissic structure with perceptible strike generally to the east of 

 north, which had led him to think it the broken and much altered 

 remains of a sedimentary rock. Salem township, Swarapscott and 

 part of Peabody are underlaid by this formation. The whole mass 

 to an unknown depth has been uplifted and shattered by internal 

 forces, which at the same time have injected the cracks and crevices 

 with fleshy or white feldspar, more or less homogeneous or mixed 

 with quartz, and in some instances mica or horneblende, according to 

 the locality. 



The cliffs along the Marblehead shore admirably illustrate this 

 point. One large cliff especially, near the line between Marblehead 

 and Swampscott, would make a solid mass if all the injected rock 

 were removed from the seams. 



Richard Bliss, Jr., called attention to some of the peculiar 

 markings which distinguish the young from adult fishes. In 

 examining some specimens recently received at the Museum 

 of Comparative Zoology, from India, which had a double 

 band on the side of the body, or rather a single line starting 

 from the gill-covers, running to the tail and then returning 

 to the gill-covers, he found this to be the young state, and 

 this the manner in which a dark, solid band was formed, and 

 became perfect as the fish reached the adult state. Another 

 species forms a band which entirely disappears leaving only 

 a spot at the head and another at the tail. A third species 

 begins with a band, which is at length resolved into cross 

 bands. These examples, he said, show the necessity of 

 studying fishes in all stages of their growth. 



Capt. N. E. Atwood made a few remarks on the habits of 

 the Blue-fish, Temnodon saltator Cuv. It was not found 

 north of Cape Cod until the year 1847. Since that time it 

 has been abundant in Eastern waters, appearing annually 

 about the fifth of June, but in his opinion is now gradually 

 disappearing. He also referred to other species, viz.: the 



