160 PALAEONTOLOGY OF ILLINOIS. 



list of the genera discovered at Burlington, in which he notes 

 ." genera of Oiuoids, and one of Blastoids as occurring in the 

 lower portion of bed No. 7, and 3 genera in No. 6. Our obser- 

 vations are to the effect that Kinderhook Crinoids in this 

 region are extremely rare, and that the authenticity of some of 

 the few that have been reported from that horizon since the 

 appearance of Dr. White's paper, is very doubtful. 



The Waverly beds in Ohio, which are probably the equivalent 

 of some member of the western Kinderhook, have yielded a very 

 interesting crinoidal fauna, to which in general features the Le 

 Grand crinoids bear a certain resemblance, though no identical 

 species have been observed. Still closer, however, is the resem- 

 blance between the Le Grand and Lower Burlington species; but 

 even among them we have not been able to positively recognize 

 more than one or two species characteristic of both beds, 

 besides the specimen from the upper layers to which we have 

 alluded. However, there are several other species which are 

 closely allied, and the same genera occur in both beds; but, as 

 a rule, those from Le Grand indicate in one way or another a 

 somewhat lower state of development. This is most readily ob- 

 served among the species of Batocrinus and DorycrimiN, in 

 which some of the generic characteristics are, as yet, partly 

 undeveloped, although the tendency toward them is manifested, 

 ll is also shown in Megistocrinus, of which both Le Grand 

 species have a subceutral anal opening like the Devonian species 

 of this genus, instead of a lateral one placed within the brachial 

 zone, as in the Burlington species. 



It appears that the LeGrand Crinoids were deposited in very 

 quiet waters, and in many cases were imbedded just as they died. 

 They occur in nests or colonies, and the genera and species are 

 commingled indiscriminately. It is therefore a curious fact, that 

 while the specimens of some species are of a pure calcareous com- 

 position and of a very light color, those of others, under pre- 

 cisely similar conditions, lying side by side with them, some- 

 times even with stems and arms intertwined, are harder and of 

 a very dark, brownish grey color. The contrast between some 

 of them, indeed, is very marked, and so far as observed, con- 



