580 
DE. CAEPENTEE’S EESEAECHES OX THE EOEA^nXITEEA. 
and what different species. Long before our dredging-net has swept round the British 
coasts, we find that what was ah’eady difficult trenches on the impossible ; and when we 
test our results by applying them to collections made in remote parts of the globe, we 
become convinced that the limited amount of our information makes that impossibihty 
absolute. The more extensive our experience, the weaher become our convictions respecting 
the limits of variation in any species^.'’ 
254. The relations of the forms belonging to the family IMiliolitidce have recently 
been investigated by Mr. "W. K. PAEKERf on the same method of extensive and minute 
comparison ; and his results are not only in perfect harmony uith those obtained by 
Professor Williamson and myself, but even go beyond them in generality. Thus in 
each of the genera Cornuspira, Hauerina, and Vertehralina, Mr. Paekee reduces all the 
reputed species to one, while he shows that even their generic differences are really but 
of small account. And he not only in like manner reduces all the reputed species of 
the genus Miliola to the level of varieties, but brings down to the same rank the reputed 
genera Spiroloculina, Biloculina, Triloculina, and Quincpieloculina ; the differences be- 
tween which, arising from asymmetrical growth, and from variations in the form and 
number of the chambers, cannot be regarded as even of specific value, the Miholine 
plan of construction being preserved throughout. “ If,” he remarks, “ the forms kept 
themselves as distinct as those represented in the diagrams, a natimalist might be 
excused for regarding them as distinct types ; but between any two of these there may 
readily be found innumerable gradations, in large and small specimens, in the smooth 
and ornamented, in the shelly or the sanded, in attenuated and in distended individuals, 
and in specimens with symmetrical or non-symmetrical, or with two- or three-sided 
shells.” I may add that I am fully prepared to endorse these conclusions; since they 
are entirely borne out by my own experience as to such forms of the Milioline tj'pe as 
have fallen under my notice. 
255. In the large group of Nodosarince which has been carefully studied by Messrs. 
T. PuPERT Jones and W. K. Parker, those gentlemen have felt themselves justified 
on the like grounds in reducing a multitude of reputed genera and species to a smgle 
type. Between the nautiloid Cristellctrice and the straight moniliform or rod-like Xodo- 
sariae, Avhich agree in essential characters of structure and mode of growth, they find 
such a continuous series of connecting links, that no line of demarcation can be any- 
where draAvn, — the straight, the curved, and the spiral forms passing gradationally one 
towards another. And the extreme forms being thus brought together, the various 
intermediate grades which have been distinguished by systematists under the generic 
names of Glandulina, LingiiJina, Bentalina, Bimulina, YaginuUna, Blanularia, Margi- 
nulina, Bimorphina, Flahellina, and Frondicidana, necessarily fiill into the same 
category:!:. 
* Introd. pp. ix, x, f Transactions of tlie Microscopical Society, 1S5S (Xew Scries, vol. vi.), p. 53. 
{ Annals of Xatnral History, Nov, 1859, p. 477 ; and Quarterly Journal of the Geological Society, Aug. 
1860, p. 302, and Nov. 1860, p. 454. 
