366 
MR. W. Iv. PARKER AND PROFESSOR T. R. JONES ON SOME 
( Gl . helicina , D’Orb. Ann. Sc. Nat. vol. vii. p. 277, after Soldani) as representing in its 
own group a type of structure which has its completeness in Carpenteria. Like certain 
varieties of Planorbulina farcta, hereafter to be described (Plate XIY. figs. 7-11), and 
of Discorbina Turbo , Globigerina has nearly symmetrical (nautiloid) varieties ( Gl. hirsuta, 
D’Orb. For. Canar. pi. 2. figs. 4-6, and Gl. pelagica , D’Orb., sp., For. Am. Mer. pi. 3. 
figs. 13, 14) : by the possession of these forms Globigerina touches isomorphically several 
other specific types, amongst which is Pullenia, its near relation, above referred to, 
typically symmetrical. Such an assumption of symmetry in these simple, vesicular, 
discoidal Foraminifers is interesting, as suggestive of a tendency to attain the more 
regular nautiloid form, normal amongst the higher forms, such as Nummulina, Cyclo- 
clypeus, Heterostegina, Polystomella, and others, which, on their part, when feebly 
developed, are apt to be asymmetrical. Indeed in this respect we have a connecting 
link between the higher and the lower group in Amphistegina, a congener of the true 
Nummulince , but simpler in structure and essentially asymmetrical. 
The foregoing observations on the relationships of Globigerina will assist us in eluci- 
dating the alliances of many of the species and varieties about to be described, lying 
between the simple monothalamous Orbulina and those highest in the scale [Polystomella 
and Nummulina ), which give the fullest expression of the type of structure possessed by 
this Rhizopodous order. 
The affinities and isomorphisms of Globigerina , however, are not exhausted by the 
consideration of the groups above referred to ; for the small and feebly developed indi- 
viduals of the typical Globigerina bulloides , which are so extremely abundant in the deep 
seas, mixed with large specimens, are imitated by the small, vesicular, weakly grown 
Textularice , Uvigerince, Pulimince, and Cassidulince ; and we might even include the dwarf 
vesicular Lituolce of deep waters (see Plate XV. figs. 46, 47, and Plate XVII. figs. 96-98). 
Figs. 1 & 2 are relatively small specimens of Globigerina bulloides , such as are found 
in shallow seas all the world over, and also (as above mentioned) in abyssal depths, 
where they are in company with large individuals ; the latter live in deep water only. 
There is but little exogenous growth on the primary perforated chamber-wall of such 
Globigerince as those before us ; but in deeper water, as a rule, a large proportion of the 
individuals have a thick deposit of exogenous shell-matter, which generally rises into 
reticulate ridges, surrounding the pseudopodian passages, and giving the surface a roughly 
honeycombed appearance. Sometimes these ridges are developed into asperities, prickles, 
needles, and even large tubules. The latter are sparsely scattered ; are formed of the 
divergent growth of the whole areola around the pseudopodian passage ; and occur on 
the symmetrical, nautiloid forms, such as occur at 1600-1700 fathoms between Malta 
and Crete. The acicular appendages arise at the junctions, or on the edges of the 
areolae, and are found on some symmetrical varieties. Such are very abundant in the 
Red Sea at from 300-700 fathoms ; and here the needles are often so long on the peri- 
pheral parts of the older chambers that they subdivide the large arched aperture of the 
last chamber into narrow oblong openings. 
