226 Miscellaneous. 
kind of complex inner wall between the great central cavity and the 
outer septate zone. This wall, however, does not completely isolate 
the septate outer zone from the central cavity, but is perforated by 
a series of round equal canals, very regularly placed one within each 
of the lateral curves of the septa, so that those on the opposite sides 
of each septum alternate with exact regularity, as do those of each 
of the two rows within each interseptal space. These canals have 
no similarity to the minute punctures of the outer wall, being 
greatly larger and very differently arranged. They do not pass 
directly through the inner wall, but are directed obliquely upward 
and inward, so that, as seen in transverse sections of the corallites, 
they present the appearance of a double row of vesicles cut across. 
Both longitudinal and transverse sections show the large central 
cavity to be without any traces of septa or columella. From these 
sections I was likewise at first led to believe this central portion to 
be also an entirely open cavity or calice, the whole length of each 
corallite ; but on sending specimens to Prof. Verrill, he called my 
attention to some obscure appearances of transverse plates in one of 
the specimens cut longitudinally, and requested me to cut others 
with the view of ascertaining whether or not these are plates. A 
longitudinal section of another specimen, however, when carefully 
polished, reveals no traces of proper transverse plates; but when 
examined by the aid of a strong magnifier, it shows the whole inte- 
rior to be occupied by a dense vesicular tissue, the walls of the ve- 
sicles being of extreme tenuity. This structure is seen in the in- 
terseptal spaces of the outer zone, as well as in the central cavity 
within. 
In regard to the affinities of so remarkable a type, it seems 
scarcely safe to express an opinion without a better series of spe- 
cimens for study. Some of its internal characters, as suggested by 
Prof. Verrill, would seem to indicate remote affinities to the Cya- 
thophyllide ; but its peculiar perforated outer wall would, on the 
other hand, appear to remove it from the primary division of corals 
including that family. . 
I am therefore led to believe it a new genus, and most probably 
typical of a new family, in which opinion Prof. Verrill concurs with 
me. For this genus I would propose the name Hthmophyllum. 
Among the specimens in the collection under examination, there 
are apparently two species of this fossil. That considered the type 
of the genus is larger and more robust than the other, and more 
conical in form, especially near its smaller end. None of the spe- 
cimens seen are quite perfect at the larger extremity. One mea- 
sures 0°37 inch at its imperfect larger end, and seems to have been 
23 to 3 inches in length. In this there are sixty septa, while its 
outer septate zone is 0:07 inch wide. Another fragment, however, 
measures 1°20 inch in diameter at the larger end, and was probably 
5 to 6 inches or more in length, with 112 septa at the larger end. 
This large fragment shows that the septate outer zone does not in- 
crease in thickness or breadth in proportion with the size of the 
corallites, since it is only 0-15 inch broad in this specimen, the in- 
