94 Messrs. W. K. Parker and T. R. Jones on the 



(as is also the habit of Valvulina) acquire some degree of rude 

 ornament from the accretion of smaller Forarninifers, sponge- 

 spicules, and prismatic fragments of molluscan shells. The 

 clear and porous shell, in small and medium-sized specimens, 

 occasionally has the pores projected as short tubes ; this is well 

 shown in a little Bigenerine Textularia in the Eocene deposits 

 of Grignon, which is closely related to T. pectinata, Reuss 

 (Denkschr. k. Akad. Wiss. Wien, 1850, i. pi. 49. f. 2, 3), from 

 the Vienna Basin, but is characterized by its relatively few pseudo- 

 podian passages being elongated as short tubes all over the sur- 

 face (fig. 2). Planorbulinafarcta has very small deep-sea varieties 

 with similar structure — for instance, Rotalia reticulata, Czjzek, 

 Haid. Nat. Abhandl. ii. 1848, pi. 13. f.7-9 ( = Siphonia fimbriata, 

 Reuss, Denks. k. Akad. Wiss. Wien, i. 1850, pi. 47. f. 6) (fig. 3) : 

 these tubuliferous Planorhulinee are not uncommon in the Red Sea 

 and elsewhere, and both recent and fossil in the Mediterranean 

 area. 



Fig. 3. 



Textularia (Bigenerina) Planorbulina fareta, 



tubulifera, P. 4" J- var. reticulata, Czjzek. 



Like some of the small varieties of Bulimina, the little, parti- 

 cularly clear Textularia frequently develope a crest with prickles, 

 as is well seen in the T. carinata, D'Orb., so common in the 

 London and other Tertiary clays. 



The large Textularia trochus of the Miocene Sands of San 

 Domingo adopts the habit of Lituola in subdividing its cham- 

 bers ; so that each lobule of sarcode must itself have been most 

 minutely lobulated. This labyrinthic condition is seen in a less 

 degree in the large T. agglutinans* of the Suffolk Crag. 



As in Bulimina, so in Textularia proper, the aperture is the 

 diagnostic mark. It is merely a low transverse arch having for 

 its base the middle of the septal plane of the penultimate 

 chamber : generally the aperture has not a thickened margin; 

 but sometimes it is slightly lipped. In many of the Textularian 

 varieties the aperture gets more and more in the substance of 

 the septal plane, passing upwards towards the apex of the con- 



* For many splendid specimens of this shell, and also of T. turris and 

 T. gibbosa, from the same deposit, we are indebted to Searles Wood, Esq., 

 F.G.S. 



