294 Messrs. Parker and Jones on 



Fig. 49 is perhaps comparable with D'Orbigny's Rotalina 

 umbilicata from the Chalk, which we refer to Rotalia proper. 

 Fig. 51, Rotalina umbilicata, is a side view of Pulv. truncatu- 

 linoides (D'Orb.), not quite so angular in its profile as the 

 recent specimen figured in ' Hist. Nat. des lies Canaries &c., 

 Foraminifbres,' pi. 2. figs, 25-27. This species is figured also 

 by Soldani, ' Testaceographia,' vol. i. p. 58, pi. 46. fig. nn. It, 

 is a variety of Pulv. Menardii, and closely related to Palv. 

 Micheliniana and Pulv. crassa, both found in the Chalk. (See 

 Phil. Trans, vol. civ. p. 393.) Fig. 52, Planulina picta, = 

 Pulv. Micheliniana (D'Orb.). Figs. 53-58 are young, and 

 59 an adult, Glohigerina cretacea^ D'Orb., a rather discoidal 

 form of Gl. hulloides, D'Orb. (53, Rotalia quaterna ; 54, R. 

 rosa ; 55, R. pacJiyomphala ; 56, R. glohosa-ampliata ,• 57 & 

 58, R. aspera ; 59, Glohigerina cretoi, referred with doubt to 

 Gl. hidloides in 1838.) The young flattish Glohigerince 

 closely resemble young Planorlndi7iai. Figs. 60-64 are young 

 and arrested specimens of Planorhulina farcta. (60, Ro- 

 talia glohulosa-tenui or, = '■^ R. glob., 1838;" 61, R. senaria; 

 62, R. densa; 63, R. glomerata, = "i?. senarial^'' 64, R. 

 cretce, rough-shelled.) 



Spongoliths and Coccoliths occur among the other figures 

 on this plate. 



The depth of sea indicated by these Foraminifera is from 

 100 to 150 fathoms. 



We must not lose sight of the large number of good-sized 

 Foraminifera from the Chalk of France and England described 

 and figured by Alcide D'Orbigny in the ' Memoires Soc. Geol. 

 France,' 1840, vol. iv. pt. 1. These were enumerated by Mr. 

 Weaver in ' Ann. & Mag. Nat. Hist.' vol. vii. pp. 395, 396, 

 with transcripts of D'Orbigny's notes on their distribution at 

 Meudon, Sens, St. Germain, and elsewhere in France, and in 

 England as far as he knew at the time. 



Of the fifty-four named Foraminifera of D'Orbigny's list we 

 should be inclined to group many as varieties, instead of spe- 

 cies ; but that does not concern us at present. Some of the 

 generic names, however, should be corrected according to 

 later knowledge. Thus No. 54, 8agrina rugosa, should be 

 Heterostomella rugosa ; for D'Orbigny had already named a 

 peculiar Uvigerine form ^^ Sagriiia'''' (8. pulchella), and for 

 this Textilarian form, departing from its true type, no name 

 but Reuss's Heterostomella has been satisfactorily given. See 

 Geol. Mag. vol. viii. p. 508. Nos. 53-51, Prof. Reuss prefers 

 to separate the sandy Textilario', such as these, under the 

 name Plecanium. No. 48, Pyrulina, is merged in Polymor- 



