(Ringueberg on the Niagara Shales. 269 
nearly all the large specimens being in the first couple of feet. 
Strophomena rhomboidalis drops from six centimeters or more 
as the maximum size in the lowest band to three in the upper 
third. The Meresti)ice are to be found in the greatest abun- 
dance in the lower portion. Colonies of the larger species at 
times multiplied largely to the exclusion of other life. After 
this first portion the Graptolltidce began to increase, though in 
varying quantity and occasionally wanting, into the itpper third. 
InocauUs however seems to go but little beyond this section. 
Some of the omnipresent species such as Spirifera niagar- 
ensis; Atrypa reticidaris ; Atrypa nodostriata ; Merstifia nitida 
and its \av. oblata; Strophowena rhoinboidalis ; Rhynchotreta 
ctmeata var americana ; Platyceras angtdatuvi ; Platystoma ni- 
agare?tse Strcptorhynchus subplantitn^ and some others, are to 
be found in varying quantities throughout the three sections 
till near its close, where they of course are few in number. 
Some extend further upward than others before dying out and 
will again be referred to in speaking of the other portions. 
Some of the rarer fossils seem to be almost entirely confined 
to this third, only an occasional specimen being found in the 
other horizons. 
Of these we may mention, Atrypa rugosa., Rhynchonella 
obtusipUcata, Anastrophia interplicata^ Callopora nummifor- 
mis, Calceocrinus radiculus^ the JEucalyptocrini., Icthyocr'nius 
liBvis, Ceratlocaris dezvyi\ jMacrostylocrinus ftdsibrachiatiis^ 
and AI. omatus^ InocauUs afiastomatica^ Conularia bifurca^ 
and the Lecanocrini except L. macropctalus. 
The Ho7nocrinus baud. This band represents the close of 
the lower third. 
Perhaps the most abundant species to be foimd is Spirifera 
niagarensis. Various other brachiopods and some of the char- 
acteristic Niagara forms are to be found here. But it is not till 
we come to a consideration of the echinodermata that we find 
distinctive features. Of this class there are more striking ex- 
amples collected together in the same stratum, to which many 
of them appear to be confined, than we have found in any other 
single portion. 
Homocrinus parvus; this graceful pigmy crinoid with 
its lone: slender thread-like columns and attenuated arms 
