MR. W. K. PARKER AND PROFESSOR T. R. JONES ON SOME 
374 
Bulimina ovata , D’Orbigny. Plate XVII. figs, 67 a , 67 b (North Atlantic). 
Among the Bulimince that fall short of the fair growth of the type ( B . Presli , Peuss) * 
are B. ovata, D’Orb., B. pupoides, D’Orb., and others which have a more or less subcy- 
lindrical form owing to the somewhat slow rate of increase in the successive chambers. 
Professor Williamson took B. pupoides as the type when describing the British Buli- 
mince, ‘Monograph,’ p. 61, &c. 
B. ovata , D’Orb., For. Foss. Yien. p. 185, pi. 11. figs. 13 & 14, is just such a varietal 
form as occurs in the North Atlantic ; on the Irish plateau, rare and small at 78 fathoms ; 
rare and very small in the abyssal area at 1776 and 1950 fathoms; rare and middle- 
sized at 740 fathoms, north of the Bank; very rare and very small at 150 fathoms in 
Trinity Bay. 
It is a British form (B. pupoides, var. fusiformis, Williamson, Monogr. p. 63, pi. 5. 
figs. 129, 130), together with the almost identical B. pupoides, D’Orb.; both of which 
are found fossil (and large) in the Vienna Tertiaries. It is large also in fossil beds at 
Jamaica (Barrett). In Captain Pullen’s Soundings from between Socotra and Kura- 
chee it is very large (sometimes thin-shelled). B. ovata accompanies the other Bulimince. 
They prefer muddy bottoms; flourishing in depths as great as 100 or 150 fathoms; and 
in the fossil state they are found in clays, corresponding to mud-beds. 
Fig. 67 a shows a slight amount of exogenous growth on the early chambers, sufficient 
to indicate the close relationship of habit between this and its better grown allies 
(figs. 68 & 69). 
Bulimina Presli , Peuss, Var. Buchiana , D’Orb. Plate XVII. fig. 71 (North Atlantic). 
In this elegant little form we find the largest relative proportion of shell-matter 
among Bulimince , which, on the other hand, are often very thin-shelled, but often 
thicker in deep seas. The chambers are here laid closely one on another, fitting well, 
nearly hiding their septa, and bearing vertical superficial ridges, sparse and strong, in 
which the marginal spines, seen in other varieties, are lost; just as spinos e Lagence, 
Nodosarice , &c. pass into ribbed varieties by modifications of the ornament. B. Buchiana 
is the most Uvigerine, both in shell-structure and shape, of all the Bulimince. 
B. Buchiana , D’Orb., For. Foss. Vien. pi. 11. figs. 15-18, is widely distributed; 
though never common. It is found in the Mediterranean; but, in comparison with 
B. ovata and B. marginata, it is rare : it is fossil near Vienna. 
On the marginal plateau off Ireland it is rare and small at 78 fathoms. 
Bulimina Presli , Peuss, Var. elegantissima, D’Orbigny. Plate XV. figs. 12-17 (Arctic). 
Some Bulimince have their segments or chambers lengthened sideways and set on very 
obliquely to the axis of the spine, the greater part of the shell being made up of thn 
last whorl of from seven to ten chambers. More especially in short and gibbose indi- 
viduals some of these many chambers are smaller than others in the whorl, and appear 
