•208 On a new Genus of Arenaceous Foraminifera. 



end of a sarcodic filament from the object to whicli it had, 

 perhaps by some suctorial power, been attached. 



Bdelloidina aggregata seems to approach nearest in form to 

 Peneroplisj on account of the chambers being all on the same 

 plane, continuous or uninterrupted by transverse partitions, 

 linear in form and tending more or less to a spiral arrange- 

 ment, with septa regularly perforated from one end to the other 

 by holes of intercameral communication (figs. 4 and 5) — and 

 perhaps by a disposition of the rug^e (which hang in prominent 

 relief from the roof) to assume in some parts a transverse 

 course, viz, across the chamber ; although this would make it 

 more like Orhiculina adunca, especially as, in some instances, 

 there is also a tendency to a double row of holes in the septum. 

 But from what has been above stated it will be seen that its 

 general form is not near so like PeneropUs or Orhiculina 

 adunca as Lituola canariensis is like Nonionina ; while the 

 uneven form and size of the sand-grains and consequent irre- 

 gularity of the cavities both in Lituola canariensis and Bdelloi- 

 dina aggregata are much the same, although the former is rusty 

 and composed of quartzose sand &c., while the latter is colour- 

 less and composed of calcareous sand &c. Then it should be 

 remembered that, as all the vitreous species of a genus are not 

 represented by arenaceous forms, so there may be some of the 

 latter which as yet have found no vitreous representatives : 

 perhaps Rhahdammina and Astrorhiza may belong to the 

 latter. 



Since the above was written I have mounted a piece of 

 Bdelloidina aggregata in which both the outer and inner sur- 

 faces of the chamber are uninjured^ and can see the openings 

 of the " labyrinthic " canals on the surface, both through the 

 latter and through the former^ by transmitted light. They are 

 extremely minute, and situated deeply in among the minuter 

 surface-particles, where they cannot be distinguished by 

 reflected light any more than through the internal openings 

 of the roof, and by testing with the direction of the light 

 can be proved to be not owing to facet-reflection of any of 

 the arenaceous particles. So this settles the question as far 

 as Bdelloidina is concerned ; and B. aggregata being exactly 

 like Lituola canariensis in sandy composition and structure, it 

 may fairly be assumed that all the Arenaceous Foraminifera 

 have pores on the surface, and therefore that the " suborder," 

 so far as it depends on imperfo ration, is exploded] while thus 

 to separate animals, merely because they happen to construct 

 their tests of foreign particles instead of calcareous material 

 secreted by their own bodies, or both together, would be 

 absurd. 



