KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 19. N!O 4. 107 



From Discorbina globigerinoides PARK, and JONES it may be difficult to keep our 

 form distinct. (Phil, trans. 155. 1, t. 1U, fig. 7). 



Fig. 262: Discorbina (Rosalina) bulloides r>'ORB. 

 Fig. 263 b: The same more magnified. 

 Fig. 263: side-view. 



Syn. Rosalina bulloides D()RB., 1839, Cuba p. 98, t. 3, figg. 2 5. 



Cymbalopora bulloides CARPEXT., Introd. 1862, p. 216. 

 Tretomphalus bulloides MOB., 1880, Meeresfaun. Maurit. u. Seych. p. 98, t. 10, figg. 6 9. 



Discorbina Poeyi D'ORB. 



Tab. VIII, tigg. 264265. 



This remarkable form seems just as little entitled to generic distinction from 

 Discorbina as the preceding. It is densely covered with ribs or knobs on its spire-side, 

 the apertural face being more scarce provided but with somewhat larger tubercles. 



It is more seldom met with on the chalk-bottom. According to Mr. D'()RBIGNY 

 who found his specimens in great abundance among sea-weed, its true home seems to 

 be in the littoral zone. 



Fig. 264: apertural side. 



Fio'. 265: side-view. 



Syn. Rosalina Poeyi D'ORB., 1839, Cuba p. 92, t. 3, figg. 18 20. 



squamosa U'ORB., ibid. p. 91, t. 3, figg. 12 14. 



Cymbolopora Poeyi CARPENT., Introd. p. 215; MOEB., Maurit. et Seych. p. 97, t. 10, figg. 1 5. 



Rosalina granulosa KARK., 1864, Leythakalk Wien. Beck.; Wien. Ak. Sitz.-Ber. 1. so, p. 710, 



t. 2, fig. 14. 



Discorbina BertheLotiana D'ORB. 



Tab. VIII, figg. 266268. 



This tiny species may be a pigmy only to a more developed form. It is extre- 

 mely thin, quite hyaline with very small and closely set pores. It is devoid of that 

 yellowish tint, so common with this genus. The shape is sometimes flat and scale- 

 like but often convex on the upper side: the hollowed apertural side with its promi- 

 nent riblike septal sutures are its most conspicuous characteristic. Sometimes those 

 ribs are sunken in septal furrows between the somewhat bulged chamberwalls. 



It is the fineness of the pores only which seems to distinguish this form from 

 some Planorbnlina; f. instance. Planorb. Bosqueti Rss. (from Maestrich-chalk) being 

 nearly isomorphous with this species. 



