Foraminifera from the Coast of Norway. 293 



We have met with a small Rosalina similar to the above in 

 the Calcaire grossier of Grignon, where Laraarck^s Discorbites 

 vesicularis was also procured. D^Orbigny quotes it as fossil at 

 Valogiies. 



D^Orbigny's model, No. 72, is a close representation of our 

 large specimens, excepting in the form of the umbilical astral 

 overgrowth, which in the former case presents neat elongate- 

 ovate lobules, instead of the less regularly defined and granu- 

 lated mass occurring in the old shells from Norway. 



17. Truncatulina lobatula^, A. D^Orb. PL X. figs. 17-21. 



Nautilus, Walker, Test. Minut. pi. 3. f. 57. 



Serpula lobata, Montagu, Test. Brit. p. 515, and Suppl. p. 160. 



Serpula nautiloides, Schrotter, N. Litterat. 3. p. 283. pi. 3. f. 22, 23 ; Gmel. 



Syst. Nat. p. 3739. 

 Lobatula vulgaris, Fleming, Brit. Anim. p. 232. 

 Truncatulina tuberculata, Sold, sp., D'Orb. Ann. Sc. Nat. vii. p. 279. no. 1; 



Modeles, no. 37. 

 Truncatulina lobata, D'Orb. Hist. Nat. Canaries, Foram. p. 134. 

 Truncatulina lobatula, D'Orb. For. Foss. Bass.Vienn. p. 168. pi. 9. f. 18-23. 



Shell discoidal, plano-convex, spire unequally shown on the 

 two surfaces, the chambers (in the typical form) overlapping on 

 one side and not on the other. Chambers broadly triangular 

 on the convex surface, subquadrate on the other, not increasing 

 rapidly in size, and subject to much variation in their propor- 

 tions. Aperture a slit at the base of the chamber, not reach- 

 ing along the overlapping portion of the chamber, but most 

 open towards the truncate or flattened face of the shell, and 

 sometimes continuous with the persistent apertures of some of 

 the preceding chambers along this face. Shell thickish, reddish 

 or livid when fresh, usually white in dead specimens, semi- 

 diaphanous, and punctured with large pseudopodian apertures. 



The specimens here figured are large individuals, preserving 

 greater regularity in the arrangement of their chambers than is 

 usually met with in specimens of their size ; yet even here the 

 outline of the shells is much affected by the varying development 

 of the segments of the animals. 



Truncatulina lobatula supplies many named varieties in me- 

 moirs both on fossil and recent Foraminifera. 



In shallow and rough water this species soon takes on an 

 irregularity of growth ; the whorls first becoming unsymmetrical 

 by intercalary and misplaced or overlapping chambers, and then 



* This form appears to be entitled to Schrotter's unfit appellation 

 " nautiloides," by the right of priority. We here propose, however, to 

 accept A. D'Orbigny's adaptation of Turton's name " lobatula," used by 

 Maton and Racket (Linn. Trans, vol. viii. p. 117)j and well known to 

 collectors. 



