THE NAUTILUS. / 



j ust above this till. Dr. Coleman, of the School of Practical Science, 



collected and sent a number of the species to Dr. Dall and C. T. 



Simpson, who identified them as follows: U. phaseolus, U. clavus U. 



pustulosus, U. pustulusus var. schoolcrafti, U. occidens(F), U.luleolus, 



U. undulatus, U. rectus, U. trigonus and U. solidus. 



Besides these a number of other shells have been found, viz. : 

 Pleurocera subulare, P. elevatum, Goniobasis, Valvata sincera, V. bi- 

 carinata, Campeloma decisum, Amtiicola, Physa, Planorbis, Pisidium, 

 Sphaerium, etc. 



A peculiar fact is the comparative rarity of Campeloma, Plauor- 

 bis and Physa, shells which are very abundant to-day in the waters 

 of the Don. Of the 10 species of Unios identified by Dr. Dall and 

 Mr. Simpson only U. luteolus and U. rectus are found here to-day. 

 Unio phaseolus and U. undulatus have been found in small numbers 

 in Lake Erie, but not in Lake Ontario. 



Three of the species, Unio pustulosus, U. solidus and U. clavus are 

 uot found to-day in the St. Lawrence drainage system at all, but are 

 confined to the Mississippi area where they are extremely common. 



The presence of the Mississippi forms seems to indicate that the 

 climate existing during the first interglacial period was somewhat 

 more southern than it is to-day, and this conclusion is also borne 

 out by the nature of the plant remains. 



Along the shores of Lake Ontario to the east of Toronto is along 

 line of cliffs known as Scarboro' Heights, composed entirely of Drift 

 deposits. Only a very few shells have as yet been found here, but 

 the beds are very rich in insect and plant remains. 



The deposits along the Don River have yielded by far the most 

 interesting results in the shell line. 



QUATERNARY FOSSIL SHELLS, LONG BEACH, CALIFORNIA. 



[Excerpts from report of Julia E. Campbell, 1896] . 



One day in April, 1896, while out for wild flowers, we drove to 

 Signal Hill, which lies back from the ocean about 2* miles. Down 

 one side of the hill runs a narrow ravine or little canon as it is often 

 called. 



While climbing up in the center of this ravine we found the banks 

 on either side literally filled with fossil shells. We secured the fol- 

 lowing species, viz. : Nassa mendica Old., N. perpinguis Hds., Den- 



