Tropidoi.eptus Fauna at Canandaigua T.ake, N. Y. 157 

 Dominant Range Frequency List for Eastern Xfw York. Composite. 



No . of Zones in 



Species. -Which Found 



1. Spirifer viiuronatus. 4 



2. .S". granulosus. 4 



3. TropidoUptus carinntus. 3 



4. Cypriardella tenuislriatus. 3 



5. Spirifer tullius. 2 



6. Athyris spiriferoides. 2 



7. Pnleoneilo const ricta. 2 



8. A'uctdites triqiwter. 2 



The remarkable fact about this list is that only eight out of the 131 

 species reported from this region occur in more than one of these 

 zones. That is, there are only eight species so far reported to have a 

 range of over 450 feet, and only two that range through the whole 

 thickness of the Hamilton in this region. 



There are two species which occur in three of the zones, four that 

 occur in only two, and the rest in only one. 



Comparing the list with the distributional list as prepared by Wil- 

 liams it is found that the first three species on both lists are the 

 same, though Spirifer granulosus and Tropidoleptus carinatus have 

 changed places. Cypricardella tenuistriatus and Spirifer tullius are 

 not in the distributional list and Paleoneilo consiricfa has changed 

 from fifth to seventh place, while Athyris spiriferoides has risen from 

 eleventh to sixth place. Nuculites triqueter has eighth place on both 

 lists. 



Now, comparing these lists, the various range frequency lists, with 

 each other and with the list of the most abundant species at Canan- 

 daigua Lake, it is seen that they have only one species in common, 

 namely, Spirifer inucronatus. The species most abundant in our 

 faunule, Clionetes scitulus is number 6 on the Eighteen Mile Creek list, 

 but does not occur in the others. Six of the species most common at 

 Canandaigua Lake are not on any of the lists. Fliacofis rami is 

 No. 2 on the Eighteen Mile Creek list and No. 5 of the Cayuga 

 Lake list. Chouetes uiucronatus is No. 8 on the Cayuga Lake list and 

 Orthothetes arctistriatus, No. 9 on the Eighteen Mile Creek list. 



Comparing the list of the most common species in this faunule with 

 the standard fauna of dominant species as prepared by Williams for 

 the New York-Ontario province it is found that four of our species 

 are on that list, occupying first, second, third and eighth places re- 



