222 
DR. CARPENTER’S RESEARCHES ON THE FORAMINI FERA. 
obtuse angles is shown in fig. 6 , and that of the acute in fig. 5 ; and in each view it is 
seen, that the divergence takes place in a plane whieh passes through the common 
centre of all three. — The specimen delineated in fig. 10 exhibits a multiple outgrowth 
of a nature resembling that shown in figs. 8 and 9 . For from the surface of the disk 
there rises a triradiate crest, formed by three vertical plates meeting one another at 
nearly equal angles, but all of them nearly perpendicular to the plane on which they 
rest. It is a very remarkable feature in this specimen, however, that the line in which 
the three vertical planes meet, is traceable at its base to the nucleus of the horizontal 
disk ; so that they all bear the same relation to it, as does the single outgrowth in the 
instances previously cited. Hence we may attribute all these monstrosities to an 
excess of productive power in the sarcode of the original nucleus, which has put forth 
its first extension, not merely in the horizontal, but also in the perpendicular direction ; 
the whole subsequent development of these outgrowths taking place after the normal 
plan, from the foundation thus laid. — it is interesting to remark, that the presence 
of such outgrowths as those now described, is far more frequent in certain localities 
than it is in others. Among some hundreds of specimens which I have examined from 
the coast of Australia, I have only met with those represented in figs, 7, 8, 9 , and two 
or three others ; the remarkable specimen delineated in figs. 5 , 6, occurred with 
another less peculiar among a comparatively small number of Orbitolites collected 
by Mr. Cuming in the Philippine Seas ; but in a small collection which I have 
inspected from the iEgean Sea, the monstrosities of this kind (of which fig. 10 was 
the most remarkable) were so numerous, that I think I am scarcely wrong in assert- 
ing that one specimen out of every three or four presented some excess*. Among 
the fossil Orbitolites of the Paris basin, the presence of a completely-semicircular ver- 
tical plate is not at all uncommon. 
63 . There may be some doubt in the first instance, as to the light in which we are 
to regard the specimen represented in Plate VIII. fig. 10; whether as a ‘ monstrosity 
by excess,’ or as the product of the fusion of two individuals : but I think this will be 
removed by a closer examination. For it is obvious, that the smaller disk, which is 
surrounded by the outer zones of the larger one, has been developed from a nucleus 
of its own; and this nucleus does not appear to have any direct connexion with the 
periphery, still less with the centre, of the larger disk : on the other hand, when we 
consider the circumstances under which Orbitolites grow 34 .), it is very easy to 
understand, that the smaller and younger individual, having attached itself in too 
near proximity to the larger and older one, should become imbedded therein (so to 
speak) by the extension of the newly-forming zones of the latter around its margin. 
* This is by no means a solitary case of the prevalence of monstrosities in particular localities. The collec- 
tion of Mr. Bean of Scarborough contains a number of curiously- distorted specimens of the common Planorbis 
marcjinatus, which have all been collected in one brook. Their peculiarities are by no means repetitions of each 
other ; and I am disposed, therefore, to regard them rather as resulting from the influence of external condi- 
tions, than as accidental varieties hereditarily propagated. 
