Tkcii'iixilei'ius Fauxa at Canandaigua Lakk, N. Y. 163 



Tropidolepttis carinatus ( Conrad ) . 



Pal. N. Y., Vol. IV, 1867, p. 407, 1)1. 62, figs. 2, 3. 



This species is very abundant in the faunule, but the individuals do 

 not attain so gieat a size here as in some other localities. The largest 

 specimen is 22 X 28 mm., while the average is somewhat below that 

 size, about 19 x 24 mm., with from 17 to 21 plications. There are 

 two varieties, one in which the plications are rounded, and another 

 in which they are more angular, and separated by wide interspaces. 



As is well known, this species is very abundant in the eastern part 

 of New York State, is common all through the section at Cayuga 

 Lake, common above the Encrinal at Livonia and Eighteen Mile 

 Creek, and very rare at Thedford, Ont. 



^■Itrypa reticularis Linn^us. 



Pal. N. Y , Vol. IV, 1867, p. 316, ])ls. 51-53 A. 

 This fossil is very rare at the Canandaigua Lake locality. It is 

 found in all the sections from Thedford to Albany Co. 



Cyrtina iiainiHonensis Hall. 



Pal. N. Y., Vol. IV, 1867, p. 268, pi. 27, figs. 1-4, pi. 44, figs. 



26-33. 38-52- 



This is a species which seems to reach a higher development in the 

 western than in the eastern sections. It is rare in eastern New York, 

 and at Cayuga Lake, common at Canandaigua Lake, fairly common 

 near the top of the Livonia section, common below the Encrinal at 

 Eighteen Mile Creek and common above the limestone at Thedford. 



The largest shell in the present collection is 9 mm. long and 13 

 mm. wide, with 16 plications. It is a little above the average size 

 for the adults from this locality. The majority of the specimens agree 

 well in size and other particulars with specimens from the other 

 Western New York localities. The specimens from Thedford, Ont., 

 the Alpena, Mich., are somewhat larger. 



Spirifer miicronatiis Conrad. 



Pal. N. Y., Vol. IV., 1867, p. 216, pi. 34, figs. 1-32. 



This species is common in this faunule, as in all the sections from 

 Thedford to eastern New York. All the adult individuals in the col- 

 lection belong to one variety. The valves are about equally convex, 

 and the cardinal extremities acute, but not mucronate. The width is 

 from two to three times the length. There are usually from 10 to 26 

 pairs of plications, depending on the size of the individual, and the 



