390 DR. J. S. BOWERBANK ON THEONELLA. [May 27, 
his researches. Thus in the second line of his generic description 
he says :—“ Internally formed of netted spicules arranged so as to 
leave an hexangular mass; the spicules subeylindrical, united at the 
inosculation of the network by a siliceous callosity.’’ This is cer- 
tainly the most incomprehensible description of a purely siliceo- 
fibrous network that can possibly be imagined; and the figure he 
has given of the reticulations of a portion of the skeleton-structure, 
P. Z. S. 1868, fig. 2, p. 566, at once contradicts his description. 
Throughout the remainder of his description he continues to describe 
the siliceo-fibrous structure as spicula. 
In the first paragraph, p. 565, the author writes :—‘‘ The sponge 
in some external characters is like the genus Macandrewia ( Dactylo- 
calyx, Stutchbury), but it differs from that sponge in not having any 
stellate spicula.” It is quite true that the Formosan sponge has no 
** stellate spicula;’’ but neither has the Doctor’s Macandrewia 
azorica; so that it is not ‘the only sponge of the family in which 
they are not discovered.” 
The author describes the long slender interstitial spicula inter- 
mixed with the fibrous skeleton; but it is a singular circumstance 
that he appears to have entirely failed in detecting the remarkable 
forms of connecting spicula on the dermis, which I have desig- 
nated as irregularly fureated patento-ternate, and which were first 
figured in the Phil. Trans. R. S. 1858, plate xxix. fig. 8, in situ, 
and fig. 9 as separated by nitric acid; and they are also repre- 
sented in P. Z. 8S. 1869, Plate V. fig. 9, in situ, and figs. 9, 10 & 
11 in the separate condition ; and it is stated in the first part of my 
paper on the siliceo-fibrous sponges that they belong to my Dacty- 
localyx Prattii. These spicula certainly form the most prominent 
specific characters of the sponge, and they are so abundant in the 
expansile dermal system of the animal that it appears singular that 
any approach to a careful examination of its structure should fail to 
immediately discover them ; nor has the author observed the minute 
entirely spined fusiformi-cylindrical spicula which are so abundantly 
dispersed on the surfaces of the dermal and other membranes of this 
species of sponge, and which are represented in Plate V. fig. 7, 
P. Z. 8. 1869. Thus the author has been led into the error of 
believing the sponge to be the type of a new genus by merely abs- 
taining from a careful and proper examination of the structural 
peculiarities of the specimen under consideration. I will not reiterate 
the description of the Formosan specimen that I have given in my 
paper, P. Z. S. 1869, in my history of Dactylocalyx Pratt; I will 
quote only a few lines comparing the two specimens under consider- 
ation: —“ The sponge is fortunately in very nearly as fine a state of 
preservation as when taken from the sea; and every organ that is 
found in the type specimen appears in abundance in the one from 
Formosa. In truth, portions of the structures taken from the one 
specimen cannot, by microscopical examination, be distinguished 
from those mounted from the other.” 
