224 Mr. R. Etheridge and Dr. H. A. Nicholson 
Koninck founded his determination, and would therefore speak 
with all due deference of his opinion; but his figure is very 
elear and evidently accurately drawn, and on this we decidedly 
found our opinion that P. compressa, De Kon., is not P. (Sphe- 
nopotertum) compressa, M. & W.: the former does not 
possess the characters assigned to the latter by its describers, 
but does distmetly exhibit those indicative of the form which 
with us, although at. first sight departing from the typical 
condition of P. cyclostoma, is nevertheless insensibly united 
with it by intermediate forms. We would illustrate our view 
of this matter as follows :—Starting with the typical form of 
P. cyclostoma, we there see the depressed expanded colony, 
composed of three or seven cells, as the case may be, the latter 
more or less all on one plane, and the flattened base. The 
next step is to an example adhering to a Dentalium, where 
we at once notice a want of the same amount of symmetry 
possessed by the two former examples, and an extension or 
lengthening of the cells, giving to the general appearance a 
certain amount of irregularity, but existing at the same time 
im conjunction with a similar external ornamentation, basab 
swellings, arrangement of the stria, and presence of the 
granulated floors to the cells. Advancing a step still further, 
we have presented to us an individual possessing all the cha- 
racters just described, but with a very much lessened point of 
attachment—again exemplified in a more forcible manner by 
the next step in the series, where the cells are longer and more 
widely separated from one another ; whilst in fig. 20 we have 
two perched upon the summit of a peduncular base of attach- 
ment, still showing traces of the concentric ridges ; lastly, as 
the most complete development of the sporting from the origi- 
nal type, we would quote Prof. de Koninck’s figure itself, 
where the irregularity of growth and elongation of the cups 
is carried to the greatest extent. In concluding this portion 
of our remarks we would simply state that we regard this 
irregularity of growth not as of specific value where all the 
other more important functional characters remam constant, 
but as simply a varietal character depending upon disadvan- 
tageous conditions of growth and habitat—an opinion founded 
not upon the examination of one or two specimens, but on that 
of a very large series. We propose to indicate this varietal 
state under the name of Paleacis cyclostoma, Phill., var. 
Koninckit, Eth. & Nich. 
The method of reproduction is particularly well exemplified 
in this species. We give an illustration of the calicular 
method of gemmation as usually met with (Pl. XII. fig. 16). 
