362 CONTRIBUTIONS TO CANADIAN PALAEONTOLOGY. 



date and have presented many of them to the Museum of the Survey. 

 Mr. Charles Schucliert, who made an unusually large collection of the fos- 

 sils of the Thedford district in 189-^) for the United States National Mu- 

 seum, has favoured the writer with a most accurate list of all the species 

 that he obtained on this occasion, and generously supplemented it with a 

 loan of specimens of forty-five of the species, for examination and compar- 

 ison. Exclusive of some undetermined and possibly undescribed polyzoa 

 (bryozoa), Mr. Schuchert's list, which, wi'th his permission, has been freely, 

 used in the preparation of this paper, includes the names of about thirty 

 species that had not previously been found in this formation in Canada. 

 Mr. B. E. Walker, of Toronto, who made a collection of the fossils of 

 the Thedford district in 1896, has also given the writer every facility for 

 examining his specimens and has lent many of them for further study and 

 comparison. To each of these obliging friends the writer's thanks are due 

 and are here very cordially lendeied. 



The present paper is a succinct statement of the results of a detailed 

 study of this new material and of additional studies of all the specimens 

 from this formation and province, in the Museum of the Survey. In 

 connection theiewith, the writer desires to (express his obligations to Mr. 

 Schuchert for several critical suggestions; to Mr. L. M. Lambe for valuable 

 as.sistance in ascertaining the minute characters of several species and in 

 checking off measurements : to the late Dr. S. A. Miller (of Cincinnati) 

 for comparing specimens of two species of Dolatocrin'tis with the types of 

 the species described by him, in connection with Dr. Gurley ; and to INIr. Vic- 

 tor AV. Lyon (of Jeffer.sonville, Indiana) for the comparison of two speci- 

 mens with the types of Megistocriniit< rugosim is his possession, and for the 

 use of an oi'iginal drawing or diagram of the plates composing the dorsal 

 cup and tegmen of that .species, by his father, the late Major Sidney 

 S. Lyon. 



CCELENTERATA. 



SPONdl/!*:. 



AsTK/EO,spo\GiA iiAiMiLTONENSi.s, Meek and Worthen. 



Aslrrrospongia HamiUonciisix, Mcnk and Worthi-n. ItilM!. Proo. Cliicigip Acad. Sc, vol. 

 1., ],. 12; and (18GK) (ie.ol. Surv. Illinois, vol. III., p. 41!l, pi. 10, 

 fig. G. 

 Whiteavfs. 1s'.)l. This vohimc, |it. H, ]). 11)8, pi. 2K, hg.s. 1 and la. 



Separate six rayed spicules, which appear to be referable to this species, 

 have been found at Thedford and Bartlett's Mills, as stated elsewhere {op. 

 cil., p. 198) in this volume. 



