DR. G. J. HINDE ON RECEPTACULITIDA. 827 
Salter amongst the Foraminifera, as allied to the family of the 
Orbitolitide ; Billings placed it with Sponges on account of a 
Supposed resemblance to the gemmule of Spongilla; it was again 
relegated to the Foraminifera by Dames, who placed it as the type of 
a family near the Orbitolitide ; and later Giimbel retained it in the 
same order, but included it in the family of the Dactyloporide. 
But since the typical forms of that family have been proved to be 
calcareous Algze, the systematic position of Receptaculites has been 
regarded as very doubtful, though F. Romer still retains it pro- 
visionally amongst the Foraminifera, as also does such an authority 
on this order as Rupert Jones. Zittel, however, rejects it from the 
Foraminifera, and leaves its position uncertain. 
LY. Tue AFFInities AND SysTeMATIC Position OF THE 
RECEPTACULITIDA. 
The different genera of this family have been variously referred, 
by those who have studied their structures, to such widely diverse 
divisions of the animal kingdom as Foraminifera, Sponges, Corals, 
Cystideans, and Ascidians, and they have also been supposed to 
belong to the vegetable kingdom and referred to fossil cones. It is 
not necessary to dwell on their supposed relationship to the three 
last-mentioned groups of animals, since it is now generally recog- 
nized to have been based on an entire misconception of the true 
structure of these fossils. The resemblance to Corals originated in 
the idea that the hollow cylindrical cells, which are really only the 
casts of the vertical spicules, were in fact the cells inhabited by 
the polyps ; and their supposed likeness to Cystideans and Ascidians 
arose from a fancied similarity in the character of the spicular 
plates of the outer surface to those constituting the external 
skeleton of these animals. Later writers have either referred them 
to Foraminifera or Sponges. The prevalent opinion of paleon- 
tologists to within a recent period has been in favour of their 
alliance to the first of these two orders; but since the particular 
division of the Foraminifera in which Gumbel placed them has 
been shown to be of plant and not of animal origin, the opinion 
has been expressed that this family should be considered as an 
extinct group without any recognizable near affinities to any other 
division of the animal kingdom. It seems difficult to understand 
the reasons for rancing any of the genera of this family under 
Foraminifera, since in no single important feature is there any 
resemblance to typical examples of this group ; neither in form, size, 
nor internal structure is there any correspondence with either fossil 
or recent Foraminifera, and only on the supposition of Salter * that 
the now solid parts of the organism were originally filled with 
living sarcode, whilst the intermediate spaces were occupied by the 
calcareous skeleton, could a strained resemblance be found between 
Receptaculites and the tamily of the Orbitolitide. Saltery himself, 
* Canad. Org. Rem. dec. 1, p. 46. 
t Mem. Geol. Survey, 1861, p. 1386. 
