484 
REVIEWS. 
only specialized cells, as in Zanolea.” Professor Agassiz seems to 
forget the parallel case afforded by Campanularia Ldveni in the allied 
order of Sertularida. In this form, according to Allman’s obser¬ 
vations, # the generative elements are situate precisely as in the 
Corynidce , while in all other Sertularians, and, consequently, in all 
other species of the genus Campanularia itself, they arise along the 
course of the radiating canals.—We would refer to the description 
and figures of Pennaria here given for a further account (the best 
indeed hitherto published) of this singular genus. Professor Agassiz 
likewise informs us “that the Hydroids described by Ayres and 
Leidy, under the names of Globiceps and Eucoryne , and by 
McCrady, under the name of Pennaria , are very closely allied, but 
not generically identical with Pennaria , though belonging to the 
same family.” 
on. n.—Eudendriuon dispar and Bougainvillea superciliaris chiefly 
differ from one another in the fact that the polypite of the former 
presents a long flexible proboscis, while in the latter the proboscis 
“ is very short, forming a mere conical papilla.” In Eudendrium the 
reproductive zooids are fixed, in Bougainvillea they detach them¬ 
selves. We are disposed to think that the Bougainvillea here 
described belongs to the genus Perigonymus of Sars.f The name 
Bougainvillea (or Hippocrene its synonym) had indeed long been 
applied to the medusoids of Tubularian zoophytes allied to Euden¬ 
drium. , while as yet their relation to the hydroid stock whence they 
were budded remained unknown. 
Pefore proceeding to notice the Sertularians of the American 
coast, Professor Agassiz, within the short compass of five pages, 
enters upon the consideration of what is undoubtedly the most novel 
and remarkable portion of his monograph. We refer, of course, to 
his proposal to place the Corallaoda tabulata, and, from analogy, the 
rugosa also, among the Hydroids. And to this step he has been led 
by original observations on the living animal of Millepora alcicornis , 
We quote the following paragraph, having immediate reference to the 
problem under discussion :— 
“ The opportunity I had while in Florida of observing Millepora alive, has 
satisfied me, however, that this genus has none of the characteristic features of the 
true Polyps, the main cavity of the body not being divided by vertical radiating 
partitions into chambers, as is the case in all the members of this class. Like the 
true Hydroids each individual has a simple, undivided cavity, with double walls. 
The individual Hydras resemble very strikingly those of Halocliaris, and, to some 
extent also, those of Coryne, and even those of the fertile Hydractinia. As in these 
genera, the mouth opens at the summit of the head, as a simple, round aperture, 
alternately opening and closing ; the digestive cavity being a simple straight cylin¬ 
der when empty, and widening somewhat when full. The outer wall is much thinner 
than the inner wall, which consists of large cells, stretching across the whole thick- 
* Notes on the Hy droid Zoophytes , A. N. H. August, 1859. 
f See Allman in A. N. H. January, 1863, p. 10. 
