1879.] 



NATURAL SCIENCES OF PHILADELPHIA. 



285 



CYATHOCRINIDiE. 



Earlier or embryonic types : 



1. Heterocrinus Hall. 



2. Iocrinus Hall. 



3. Anomalocrinus Meek & "Worth. 



Typical Cyathocrinidse: 



6. Gyathocrinus Miller. 



7. Leeythocrinus Zittel (J. Miiller). 



8. Gissocrinus Angelin. 



9. Arachnocrinits Meek & Worth. 

 10. Vasocrinus Lyon. 



Poteriocrinus type: 



14. Poteriocrinus Miller. 



Subgenus Scaphiocrinus Hall 



(modified by W. & Spr.). 

 Subgenus Parisocrinus W. &Spr. 

 Subgenus Pachylocrinus 



W. & Spr. 

 Subgenus Scytalocrinus W. & Spr. 



4. Hybocrinus Billings. 

 Subgenus Homocrinus Hall. 



5. Dendrocrinus Hall. 



11. Ophiocrinus Angelin. 



12. Botryocrimis Angelin. 

 Subgenus Sicyocrinus Angl. 



13. Barycrinus Wachsmuth. 



Subgenus Decadocrinus 



W. & Spr. 

 15. Graphioerimis de Kou.&Leh. 

 Subgenus Bursacrinus 



Meek & Worth. 

 Subgenus (?) Phialocrinus 



Trautschold. 



1 Since writing our classification, Prof. Zittel of Munich, with whom we 

 have exchanged notes informs us that he has separated the genera which 

 we have united under Cyathocrinidse into four families. (Handbuch der 

 Petrefactenkunde, 3te Lieferung, now in press.) 



without pinnulae, arms covered with plates. 



1. Hybocrinidse 



2. Cyathocrinidse 



3. Poteriocrinidse > with piunulfe . 



4. Heterocrinidse 5 



"We doubt whether this division can be maintained practically. Hetero- 

 crinus is certainly more closely related to Hybocrinus, which he disposes 

 under a separate family, than to Graphiocrinus, Philocrinus, Erisocrinus, 

 and Stemmatocrinus with which he groups it. The variety of Poteriocrinus, 

 which we have proposed to call Scytalocrinus, has such close affinities to 

 Graphioerimis that it might well be doubted whether it would be considered 

 as a subgenus of Poteriocrinus or Graphiocrinus. If a division of the Cya- 

 thocrinidse should prove desirable, it would seem to us more natural to bring 

 together Heterocrinus with Hybocrinus and Anomalocrinus, and to place 

 Graphiocrinus and allied genera under the Poteriocriuidaa ; but this would 

 interfere with the division according to pinnulse. The difficulties in the 

 way of a subdivision, which we have discussed at length in our general 

 remarks on the family, do not seem to us to be obviated by the proposed 

 arrangement of our distinguished colaborer. 



