246 Mr. H. J. Carter on the Structure of the larger Foraminifera. 



7. Adeorbis suturalis, A. Adams. 



A. testa ovato-discoidali ; spira prominula, albida, tenui, semipellucida, 

 striis incrementi radiatim ornata ; anfractibus rapide crescentibus, 

 prope suturas subcarinatis, ultimo ad peripheriam subangulato, 

 suturis canaliculatis ; umbilico angusto, margine rotundato ; labro 

 mediocri. 



Hab. Tsu-Sima ; 26 fathoms. 



8. Adeorbis japonica, A.Adams. 



A. testa discoidali ; spira depressa, alba, nitida, tenui, semidiaphana, 

 radiatim striata; anfractibus regulnviter crescentibus, convexius- 

 culis ; umbilico patulo, margine valde carinato ; labro mediocri. 



Hab. Mino-Sima; 63 fathoms. 



9. Adeorbis nanula, A. Adams. 



A. testa ovata, subconvexa, tenui, semidiaphana, nitida ; anfractibus 

 rapide crescentibus, convexiusculis, ultimo subventricoso, ad peri- 

 pheriam angulato ; umbilico angusto, margine rotundato ; labro 

 mediocri. 



Hab. Mino-Sima ; 63 fathoms. 



Shanghai, China, 

 January 1, 1861. 



XXVII. — On the Structure of the larger Foraminifera. 

 By H. J. Carter, Esq., F.R.S. 



In a paper on the Structure of the larger Foraminifera, read 

 before the Bombay Branch of the Royal Asiatic Society (April 11, 

 1861), the author sums. up his observations on the discoidal 

 Foraminifera as follows : — 



Test. — The test is situated in the substance of the animal, 

 and (in Operculina) consists of the spiral or horizontal lamina 

 and the marginal cord. The spiral lamina, again, is divided 

 into the parts which cover the chambers and those which cover 

 the interseptal spaces : the former are pierced with close-set 

 vertical tubuli, and the latter with more or less scattered minute 

 branches of the interseptal canals. Besides this, there are non- 

 tubular spaces or puncta, more or less regularly scattered over 

 the chambers and interseptal spaces, which answer to the external 

 ends or bases of conical columns of condensed shell-substance, 

 intended apparently for strengthening the test; and these are 

 accompanied, in some species of Nummulites, by a horizontal 

 branch-work of the same material, which gives them very much 

 fiie appearance of the lacunae and their canaliculi in bone; yet 



