ECHINODERMATA. 35 



ORDER VI. """CYSTOIDEA. 



Sub-ord. 1. Aporitidae. Cryptocrinus, Malocystites. 

 Sub-ord. 2. Diploporitidse. Splicer onites, Glyptosphcerites. 

 Sub-ord. 3. Rhombiferi. Caryocrinus, Ifemicosmites, 

 Uckinoencrinus. 



(Von Buch, Ueber Cystideen, Berlin, 1845 ; Billings, On the Cystidea of 

 the Lower Silurian Rocks of Canada, 1858.) 



ORDER VII. *BLASTOIDEA. Pentrcmites, Nucleocrinus, Gran- 

 atocrinus. 



(Ferd. Roemer, Monographic derfossilen Crinoiden-familie der Blastoiden 

 und der Gattuny Pentatrematites im Besonderen, Berlin, 1852.) 



