Ulrich on Correlation of the Lower Suuriaii. 109 
iniddle there is one which holds many specimens of a new 
species of Alodiolopsis. It iisnally occurs in the shape of casts 
of the interior, but examj^jles retaining the shell are not uncom- 
mon. Some feet higher there are several thin layers holding 
iin abundance of a small hemispheric species of Prasopora,, one 
inch or less in diameter, while at the top I have met with a 
layer about one foot in thickness in which the fossils ( Tetradi- 
i4m and several Gasteropoda are silicified. The Lingulcs are 
4dmost restricted to the shaly lavers. Following is a list of the 
principal species: 
Tctradiuvt tninit^ Safford. Lim^iihi chlcri Whitf. 
Prasopora lycopcrdon V anuxcm (rare) Bcllcrophon bilol>atu.< Sou. 
" hcmisplicrica ti. sp. Rnpbistoma lapicida Salter. 
^ygospira recurvirostris Hall. MurcJiisoma mtllcri Hall (typical) 
lAniJ^ida riciuiformis Hall. Modiolopsis oviformis (n. sp.) 
" curt a Hall. Tentaculites obliquns (n. sp.)' 
Beds VII, These beds are usually darker than the preced- 
ing, being often dark blue, with the shales sometimes even 
black. The latter are commonly brownish, weathering to a 
<lark drab or gray. The whole is about sixtv feet thick and 
composed of thin, irregularly bedded, highly fossiliferous lime- 
stones, with thin, shaly partings. After an exposure of several 
years the slabs are nearly always small, and characterized by 
their rough nodular surface. They decompose rather rapidly 
and give rise to the best soils in the state, for it is upon them 
mainly that the famous blue-grass attains its most luxuriant 
j^rowth. 
These l)cds are well exposed in the cuts along the C, vS, R, 
R, between four miles south of High Bridge and Burgin, two 
miles farther south. Also in several cuts between two and a 
half and five miles south of Burgin, where they again form 
the surface rock, after having been covered bv succeeding lay- 
-ers for perhajDS a mile and half. Natural exposures are not 
common, because of the level lands that have resulted from 
their uniform dismtegration. Some fairlv good exposures are 
seen at Frankfort, 
Fossils are very abundant, particularly so the Bryozoa, many 
'This species is abundant in certain layers. It is about 10 mm. long, 
i.o mm. in diameter, slightly curved, and marked with rounded annula- 
tions about 15 to 5 n^in., which pass obliquely around the shell. 
