30 GEOLOGICAL AND NATURAL HISTORY SURVEY OF CANADA. 



from several localities in Ohio and Indiana, and a year or more ago 

 it was found at -a corresponding horizon in the Hudson River group at 

 Wilmington and Savannah, 111. 



MoNTicuLiPORA Wetherbyi, Ulrich. 



Monticulipora Wetherbyi, Ulrich, 1882, Journ. Cin. Soc. Nat. Hist., vol. 5, p. 

 239, pi, 10, fig. 4-45. 



Two examples of a species of 3fonticuUpora, growing upon the frond 

 of Pachydictya rnagniporaj (n. sp..) occur among the material from St. 

 Andrews. The surface of one of them was ground away, so as to exhibit 

 fairly distinct tangential and vertical sections. As near as these per- 

 mit me to determine, the specimensdiffer from the types of M. Wether- 

 byi (derived from the Birdseye limestone of central Kentucky) only in 

 having the acanthopores somewhat less strongly developed. In other 

 respects there seems to be perfect agreement. 



St. Andrews, Manitoba, Dr. R. Bell, 1880. 



HOMOTRYPA, Sp. 



Four or five fragments of a smooth species of this prolific genus are 

 contained in the Manitoba material before me. They are unquestion- 

 ably identical with an undescribed form not unfrequently met with in 

 the upper beds of the Hudson River or Cincinnati group at various 

 localities in Ohio, Indiana and Illinois. Being closely related to other 

 species, some of them also undescribed, I prefer to leave it unnamed 

 until an opportunity is otfered of describing its internal characters. 

 Without good figures it might not be recognized, a remark which is 

 peculiarly applicable to species of Homotrypa. 



The Manitoba specimens were collected by Mr. A. McCharles at Stony 

 Mountain, in 1884. 



DiPLOTRYPA WeSTONI. (N. Sp.) 



Plate VIII., figs. 4-45. 



Of this peculiar species the specimen figured is the only one seen. It 

 afforded the following characters : Zoarium a sub-hemispherical mass, 

 about thirty-four mm. in diameter and twenty mm. high, with the 

 lower side concave, and probably lined with an epitheca. The upper 



