Miscellaneous. 409 
Sponges,’ p. 757 (by a misprint it came out p. 717), as follows :— 
“In the tubular Huplectella aspergillum and in allied forms the 
central cavity . . . appears as a preoscular tube.” In other words, 
the central cavity is of exhalant nature. Well and good! But on 
the very next page of the same work we read, ‘‘ The cribriform 
membrane which is stretched over the wide terminal pseudoscula 
of Dendrilla cavernosa, covering the entrances to the vestibular 
cavities, is very remarkable. I do not hesitate to compare it 
directly to the terminal sieve of Huplectella aspergillum. I think 
it may not be impossible that in some of the cup-shaped or tubular 
Hexactinellida the central cavity is, like that of Dendrilla cavernosa, 
an inhalant vestibule, and not a preoscular tube.” That is to say, 
the sieve-membrane covering the central cavity in Hwuplectella is 
compared directly with a similar sieve covering an inhalant space in 
another sponge. The only rational conclusion from such a homology 
appeared to me to be that the central space in Huplectella was to be 
regarded as inhalant also. In commenting on these statements I 
concluded by saying it was not necessary to point out the contra- ‘ 
dictions in which the author had landed himself. I only hope I 
have made it clear how I gathered from Dr. von Lendenfeld’s state- 
ments the meaning I imputed to them. Ido not quite follow Dr. von’ 
Lendenfeld’s meaning when he speaks of a “ hostile motive” having 
prompted me in my interpretation of his statements, and cannot 
but deprecate the introduction of personalities into a_ scientific 
argument. 
Zoological Station, Naples, 
April 8, 1892. 
On some Specimens of Dendroclava Dohrnii, Weismann. By 
Dr. Rarrartro Zora. 
On the 25rd October, 1891, the Director of the Zoologica! Station at 
Naples, with his usual courtesy, gave me some hydroids (Sertularella, 
Eudendrium, Campanularia) which the fishermen had brought from 
the coasts of Nisida. Amongst these were a few small colonies of 
hydrosome which at first sight appeared to me to be very similar to 
Corydendrium, although perhaps the zooids were somewhat smaller 
than those of Corydendrium parasiticum. One of these colonies 
grew from the stalk of a Campanularia in the same manner in 
which the trunks of Corydendrium parasiticum spring from those of 
Eudendrium, so that the resemblance between the two was the 
more striking. 
On bringing these hydroid colonies under the microscope, I 
observed some medusoid buds under the neck of the zooids ; and in 
this, as well as in other respects, the hydroids corresponded exactly 
with the Dendroclava Dohrnit described by Weismann, whose 
observations, as far as I know, have never yet been called in 
question. 
These colonies were about 2 centimetres in height, somewhat 
