Miacellaneous. -109 



Bpouges,' p. 757 (by a misprint it came out p. 717), as follows : — 

 " In the tubular Euplectella aspeniiUxnii and in allied forms tho 

 central cavity . . . appears as a preoscular tube." In other words, 

 the central cavity is of exhalant nature. "Well and jrood I liat on 

 the very next page of the same work we read, '• The cribriform 

 membrane which is stretched over the wide terminal pseudoscula 

 of Dcndnlla cavernosa, covering the entrances to the vestibular 

 cavities, is very remarkable. I do not hesitate to compare it 

 directly to the terminal sieve of Euplectella asperrfillum. I think 

 it may not be impossible that in some of the cup-shaped or tubular 

 Hexactiiu'Uida the central cavity is, like that of Denrlrilla cavernosa, 

 an inhalant vestibule, and not a prteoscular tube." That is to say, 

 tho sieve-membrane covering the central cavity in PJuplcctella 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 EnplccteVa was to be 

 regarded as inhalant also. In commenting on these statements 1 

 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 1 imputed to them. I do not quite follow Dr. von 

 Lendeufeld's meaning when he speaks of a "• hostile motive " having 

 prompted me in my interpretation of his statements, aud cannot 

 but deprecate the introduction of personalities into a scientific 

 argument. 



Zoological Station, Naples, 

 April 8, 1892. 



On some Specim<:ns of Dendroclava Dohruii, Weismann. By 

 Dr. Kafvaello Zoia. 



On the )l''ivA October, 189 1, the Director of the Zoological Station at 

 Naples, M'ith his usual courtesy, gave me some hydroids {SertnlareUa, 

 Eudendriiuii, Campnudaria) which the fishermen had brought from 

 the coasts of Nisida. Amongst these were a few small colonies of 

 hydrosomaj which at first sight appeared to me to be very similar to 

 Cori/dendrium, although perhaps the zooids were somewhat smaller 

 than those of CorydendriiDn parasiticum. One of these colonies 

 grew from the stalk of a Oampanularki in the same manner in 

 which the trunks of Corydendrium parasitkuni spring from those of 

 Eiidendriam, 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 Dohrnii described by Weismann, whose 

 observations, as far as I know, have never yet been called in 

 question. 



These colonies were about '2 ccutimctres in height, somewhat 



