238 



PALEONTOLOGY OF ILLINOIS. 



FAMILY MONAKID^ Marshall 

 ASTILEOSPONGIA Roemer, 1860, 



A. hamiltonensis Meek and Worthen. 

 A. meniscus Roemer... 



FAMILY POLLAKIDvE Marshall 



HYALOSTELIA Zittel, 1878. 



* H. delicatula Ulrich... 

 H. metissica Dawson. 



* H. solivaga Ulrich 



>* 



ASTROCONIA Sollas, 1881. 

 A. grant! Sollas 



FAMILY BRACHIOSPONGID^E Beecher. 



BRACHIOSPONGIA Marsh, 1867. 

 A. digitata Owen, sp 



FAMILY RECEPTACULITID^ Hinde. 

 RECEPTACULITES DeFrance... 



Mr. S. A. Miller gives a list of 24 species of 

 this genus in his "American Palaeozoic Fossils" 

 (edition of 1883). How many of these will 

 prove to be valid species, and what forms, if 

 any, are referable to Ischadites Murchison, 

 and Acanthoconia Hinde, I am unable to say. 

 I am, however, aware that Dr. Hinde has re- 

 viewed nearly all the American species in his 

 valuable memoir on the Receptaculitidse, but 

 as this work is, unfortunately, not within 

 my reach at present, I must be content with 

 simply referring the reader to it. 



