218 On Foraminif era found in and about Tubipora miisica. 



tion shows either that the section had not passed through the 

 " median plane," or that the hehx is trochoid^ which is really 

 what the section does represent, judging from those that I have 

 made myself of this Foraminif er. 



EXPLANATION OF PLATE XIII. (figs. 9-29). 



Fig, 9. Carpenteria monticularis, n. sp., on a portion of Tuhipora musiea. 

 a, simple form ; h, branched or dendritic form ; c c, apertures re- 

 spectively ; d, lines or grooves marking the eeptal limits of the 

 chambers. Magnified four diameters. 



Fig. 10. The same : square indicating the natm-al size. 



Fig. 11. The same : supposed embryonic form, a, prolonged tubular 

 aperture ; h, last-formed or upper chambers foraminated ; c, lower 

 or previously formed ones. Scale l-48th to l-1800th inch. 



Fig. 12. The same : portion of surface to show the uniform pore-tubula- 

 tion of the shell : same scale. Diagram, a, sm-face-ends of 

 three pore-tubes, more magnified, to show the pore in the centre 

 respectively : scale l-12th to l-1800th inch. 



Fig, 13. Carpenteria balaniformis : portion of surface of the shell, to show 

 the interrupted pore-tubulatiou, in contrast to that of fig. 12. a, 

 circular interstices ; b, reticulated framework ; c, sm-face-ends of 

 three pore-tubes, more magnified, to show the pore in the centre. 

 Same scale as the foregoing respectively. 



Fig, 14. Polytrema miniacemn, var. album : portion of basal layer, to show 

 its commencement from an embryonic chamber in a helical fonn. 

 «, embryonic portion ; b, subsequently formed chambers. Scale 

 l-2'4th to l-1800th inch. 



Fig. 15. The same, var. cinnainoimim, showing the same, a, embryonic 

 portion ; b, subsequently formed chambers. Scale l-48th to 1- 

 1800th inch. 



Fig. 16. Planorbulina larvata, showing the same, a, embryonic portion j 



b, subsequently formed chambers. Same scale. 



Fig. 17. Planorbulina vulgaris, showing the same, but with the embryonic 

 portion a, outside the plauorbuline chambers, bbb, planorbuline 

 chambers ; c c, their characteristic apertures. Same scale. 



Fig, 18. Tinoporus hacidatus, var. sph(sroidalis, nat. size. 



Fig. 19. The same, var. hemispha;ricus, on a portion of Tubipora musiea, 

 nat. size. 



Fig, 20. The same (spheroidal variety), much magnified, to show : — rt, 

 natural surface ; 5, hemispherical section ; c, radiating columns 

 of chambers ; d, incomplete chambers. Diagram. 



Fig. 21. The same : portion of the hemispherical section, more magnified, 

 showing : — a a a, chambers ; h b, partitions of solid shell-substance ; 



c, foraminated or pore-tubulated plates ; d, sides of the chambers 

 pierced by one or more holes of iutercameral commimication ; e, 

 incomplete chamber. Diagram. 



Fig, 22. The same, circumferential ends of three columns in juxtaposi- 

 tion, showing, a, the ^ncomplete chamber, and b b, the forami- 

 nated or pore-tubulated complete ones ; corresponding with the 

 diagi'am below. 



Fig, 23. Valvtdina ?, textularian, nat. size ; from the specidien of 



Tubipora musiea. 



Fig. 24. The same : half of a horizontal or transverse section, seen from 

 vdthiu, to show (in the right half only, the other having been 

 left blank for convenience) : — a, vertical view of the ends of the 



