No. 5.] DAWSON — FORAMINr;ERA, MANITOBA. 258^ 



The common spiral Foraminifcr in the Pembina Mountain- 

 specimens, is Discorhinn (Rotnlla) g/ohiihtris, D'Orb. sp., and 

 is probably identical with Rotalinn, {RofalUi) ghhularls, cha- 

 racteristic of and very common in the upper and lower chalk of 

 En<;;land. This form is also common in the specimens from 

 Nebraska, and must be the same as PhinnrhuUna globnJosay 

 lecogni/ed by Parker and Jonos from Khrcnberg's figures as 

 occurring in the Mississippi Crctaceouh.'^ Thcpe authors there 

 remark that PhinorJmlina globulosa, Ehr. sp. "must not be 

 regarded as worth much, being a very minute Rotaline, and 

 such a form as several species might present in their earliest 

 stage of growtli." It forms, however, a well marked type 

 in the Maiiitob:i and Nebraska deposits, and as no larger 

 examples occur, must bo regarded as an adult though depau- 

 perated variety. It is common everywhere at the present day» 

 In the North Atlantic it is best developed from the shore down to 

 50 or 70 fathoms. It becomes flatter at greater depths. The 

 specimens from ^Manitoba are considerably flattened. 



A second Rotaline, smaller and flatter than the rest, and with 

 more delicate chambers and more in a wjiorl is rcfcral)le to 

 Phmoi'bnlliKi (^Pldiinliiut) (tvinihioisis, D'Orb. sp., included 

 under P.f'irctn by Messr-*. Parker and Jones, and belongs to 

 the series of small quasi Kotalian and Nautiloid forms, more or 

 less symmetrical, which they state f to be very common in some 

 secondary deposits, and abundant in the present seas at from 

 100 to 1000 fathom?. J\ <n-iminensis la common in the English 

 chalk, in that of Miien, Denmark, and doubtless elsewhere. It 

 is also found in Tertiary and recent deposits. GliJ>ig<:i'iiHr — 

 referable to G. crftncea, J>lso occur, and an examination of a 

 larger qumtity of material than that now at my disposal would 

 no doubt bring to light many additional form-^. 



The general facies of the foraminiteral fauna of these Creta- 

 ceous rocks of ^lanitoba and Nebraska singularly resembles that 

 of the ordinary English chalk. Both abound in Textularine 

 and Rotaline forms of similar types, the most abundant ia 

 both being the form with globose chambers, and each having 

 its rarer analogue with chambers flattened and more delicate. 



To the bodies now included under the general name Coccolithsy. 

 attention has only been prominently drawn of late years. Ehren- 



• Quart. Jour. Geol. See. 1872. 



t Memoir on Atlantic and Arctic Forams. 



