168 
PALAEONTOLOGY OP NEW-YORK. 
Productella hirsuta, var. rectispina. 
PLATE XXIV. 
A group of figures at the lower part of this plate were originally sepa¬ 
rated, under the impression that they were a distinct species; but later 
examination has induced me to unite them with this as a variety, till 
more positive differences can be ascertained. They occur in a fine fissile 
and almost slaty sandstone in the Chemung group in the south part of 
Steuben county, and a few specimens from other localities have the same 
characters : these hold a somewhat higher position in the series than 
those from Philipsburgh. The condition of their preservation in a coarse 
matrix has given a somewhat different aspect to the surface markings, 
and the spines on the hinge-line, when preserved, are vertical; while 
in the specimens from Philipsburgh and the Blossburgh railroad, the 
spines are always directed obliquely outwards. The same feature of dis¬ 
tortion or inequality on the two sides of the beak prevail in all the spe¬ 
cimens from this locality in Steuben county, as well as in those of Alle¬ 
gany county and other places. The casts or impressions in this rock 
have a more Coarsely pustulose or wrinkled surface ; and in some imper¬ 
fect specimens of the same type from Meadville (Pennsylvania), the 
valves have had a diameter of more than two inches, and the surface is 
strongly wrinkled on and near the cardinal margins. 
A single individual in a setnicalcareous matrix from Troup’s creek near the 
Pennsylvania line, in the vicinity of the sandstone specimens, preserves the sur¬ 
face characters in greater perfection than any specimen elsewhere observed. An 
enlarged view of a portion of this shell is given in one of the figures. 
