12 PROCEEDINGS OP THE ACADEMY OF [1884. 



treated, gives a yellow light ; from which he concludes that the 

 different colors depend upon different crystalline states, the com- 

 position remaining the same. 



The speaker had been fortunate enough to observe the rare phe- 

 nomenon of the phosphorescence of snow, having seen a snow- 

 covered Alpine mountain shining at night as though illuminated 

 by moonlight. This beantiful appearance lasted for about half 

 an hour only, and was confined to a single mountain. Here again 

 the phosphorescence, although of quite a different kind from 

 either of those mentioned above, was purely physical, depending 

 upon the assumption of a certain crystalline condition of the 

 snow. 



In general, the phosphorescence of a substance may be said to 

 depend upon an alteration in its molecular state of aggregation. 

 In the case of " Hell-fire rock " it appears to be the result of a 

 disturbance of its loosely aggregated crystalline particles, whether 

 such disturbance be produced by percussion, friction, heat or 

 decrepitation. 



The New Jersey Coast after the storm of Jam. <?, 188 Jf^. — Pro- 

 fessor Leidy stated that, in company with Dr. Sharp and Mr. 

 Ford, he had made a trip to Atlantic City, N. J., to observe the 

 result of the recent storm on the marine animals of our coast. 

 The shore at the highest line reached by the tides was for miles 

 covered with incalculable numbers of the Beach-clam, Mactra 

 solidissima. These in many places formed extensive patches 

 actually closely paved with the clams. Besides those visible, it 

 is probable as many or more were covered by the sand thrown 

 up with the clams. Until this evidence of the storm, he had no 

 suspicion that the mollusk was so exceedingly abundant on the 

 coast, though he had been well aware that it was very common, 

 and had repeatedly seen large quantities thrown on shore under 

 similar circumstances. With the Mactra were other mollusks, 

 and, though numerous enough, they appeared to be few compared 

 with the former. These were Fulgur carica and F, canaliculata, 

 Natica heros and N. dupHcnta, and Nassa obsoleta. Hermit 

 crabs were also numerous, Eupa gurus poUicaris in shells of 

 Natica and Fulgur, and E. longicarpus in shells of Nassa The 

 former shells had attached abundance of (Jrepidula wiguifornns, 

 and occasionally on the outside a C. fornica'ta. Of other crabs, 

 the Spider-crab, Libinia canaliculata and Platyonichus ocellatus 

 were frequent. A few half-grown Horse-shoe crabs, Limulus 

 polyphemus, were also observed. A few bunches of Mytilus 

 edulis were occasionally met with. 



It seemed remarkable that certain common m Husks were con- 

 spicuously absent, as the Oyster, Ostrea virginiana, the Clara, 

 Venus rriercenaria^thG Squirt-clam, My a arenaria, and the Horse 

 mussel, Modiola jylicatula. Scarcely any annelides were observed, 



