75 



In tlie SubcarboniferouB system we find Actinocrinus, Agari- 

 cocrinus, Alloprosallocrinus, Amphoracriims, Batocrimis, Blairo 

 crinus, Dorycrinus, { Mefjistocrinus ahove mentioned) Physefocrinus, 

 S(ini2)sonocrinus, Shumardocriims, Steganocrinus, and Strotocrinus. 

 In this disposition of the genera we regard Eretmocrinus as a 

 synonym for Batocrinus and Teleiocrinus as a synonym for 

 Strotocrinus. 



Blnirocrinus, Sampsonocrinus and Shumardocrinus are confined 

 to the Chouteau limestone. There are four species of Blair ocrinus, 

 each of which bears twenty arms, one species of Sampsonocrinus 

 that has nineteen ambuiacral openings to the vault, and one species 

 of Shumardocrinus that has five ambuiacral openings to the vault, 

 and the free arms are not known in either species. There are 

 five species of Actinocrinus described from the Chouteau lime- 

 stone and Kinderhook Group, having twenty, twenty-two, and 

 thirty ambuiacral openings to the vault. Four species of Agari- 

 cocrinus, having nine and ten ambuiacral opeoings. Four species 

 of Amphoracrinns having six and ten ambuiacral openings and 

 one with twenty arms. Three species of Batocrinus, having 

 twenty ambuiacral openings. And three species of Dorycrinus 

 having respectively twelve, fourteen and eighteen arms. 



Fliysetocrinus. Steganocrinus and Strotocrinus are confined to 

 the Burlington Group. There are nine species of Fhysetocrinus, 

 having twenty, thirty- four, forty and fifty arms. There are four 

 species of Steganocrinus, having five large, ambuiacral openings 

 to the vault and numeious armlets of a peculiar character. And 

 there are twenty species of Strotocrinus, having twenty, twenty- 

 six, thirty, forty, fifty, sixty, seventy, eighty and one hundred 

 arms There are fifty-three species of Actinocrinus, described 

 from the Burlington Group, having ten, twenty, twenty-one, twenty- 

 two, twenty-four, twenty-nine, thirty, thirty-six and forty arms; 

 the greater number have twenty and thirty arms. Eighteen spe- 

 cies of Agnricocrinus, having ten and twelve arms. Six species of 

 Amphoracrinns, having ten, twenty and twenty-two arms. One 

 hundred and eleven species of Balocfinus, having eight, ten, 

 twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen' 

 nineteen, twenty, twenty-one, twenty- two, twenty-three, twenty- 

 four, twenty-six and twenty-seven arms, the prevailing species hav- 

 ing eighteen, twenty and twenty-two ambuiacral openings to the 



