REVIEWS. 
265 
with the Bryozoa (or Polyzoa). This question is discussed by him at con- 
siderable length in his new treatise, and he still holds, in opposition to the 
views of Prof. Lindstrom and Busk, and of Mr. Waters, that there is no 
unmistakable evidence of the Bryozoan nature of the Monticuliporidse. 
With regard to their relationship to the genus Heteropora especially, upon 
which much stress has been laid, he says, 1 It is clear that the points of 
likeness between the two are by no means so weighty as the points of 
difference. On t the one hand, we have a strong natural resemblance, a 
general similarity in the mode of construction of the skeleton and an agree- 
ment in the fact that in both genera the colony consists of two sets of 
tubes, crossed by transverse partitions. Such transverse partitions of the 
tubes (or, as we may loosely call them, “tabulae”) occur, however, in 
organisms of such exceedingly diverse affinities, that we can, admittedly, 
attach no value to the last-mentioned of the above resemblances. ... On 
the other hand, to set against the mostly superficial points of resemblance 
above noted, we have a number of fundamental structural differences. Thus, 
in Monticulipora the walls of the tubes are imperforate ; there are no traces 
of radiating spines or “ septa,” and in the dimorphic or trimorphic species 
there are usually important differences as regards the different groups of 
corallites. In Heteropora , on the contrary, the walls of the tubes are 
traversed by a very remarkable and exceptionally developed canal system ; 
the tubes possess in their outer portions a well-developed series of radiating 
spines . . . and the interstitial tubes are in no way structurally different 
from the proper zooecia.’ From these and other considerations, the author 
declares, without denying the possibility that Monticulipora may belong to 
the Bryozoa, that his specimens lean decidedly towards the Coelenterata 
1 as a proper resting-place for the genus.’ 
In the systematic and descriptive part of his present work, Prof. 
Nicholson makes no attempt at a monograph of the curious and puzzling group 
of fossils to which he has devoted so much attention, but simply endeavours 
to define clearly and accurately the species with which he is acquainted, and 
the generic and sub-generic groups to which they are best referred. His 
family Monticuliporidse is made to include only the single genus from 
which it takes its name ; and the other named groups of allied organisms, 
some of which were distinguished even before D’Orbigny established his 
genus, are treated provisionally as sub-genera. Of these there are Fistuli- 
pora , M‘Coy, with which Callopora, Hall, is synonymous; Constellaria , 
Dana, including Stellipora, Hall, and Dekayia, M. Edw. and H. ; and these 
three groups are regarded by the author as so far differing from the rest that 
their distinction may be considered of more weight, and they thus acquire 
a sort of quasi-generic value, in opposition to Monticulipora proper, which 
in its turn includes the subordinate groups, Diplotrypa, Heterotrypa, Mono- 
trypa, Prasopora , and Peronopora — the last-named here proposed for the 
first time. 
It would be manifestly out of place here to enter upon a criticism of 
the course adopted by Prof. Nicholson, if, indeed, anything of the kind 
could be profitably undertaken without a long study of the very objects 
investigated by him. The reader will easily see, from what is stated above, 
that the subject is an exceedingly difficult one, and that the attempt at 
