NO. 1255. NE W SPECIES OF ALG.E— WHITE. 269 
demand.s most consideration is the genus Codrnm Stackhouse, to which 
reference has already been made in the description of Bnth<>treph)K neio- 
11 1(1. In Cod iu III we find spong-e-like fronds which may be simple or 
branched, and which are composed of a mass or plexus of innumerable 
slender, inextricabh' tangled or interwoven and irregularly branched 
unicellular filaments whose ramules form the surface of the frond. 
Near the center of this mass of curled and branched filaments which 
gives form to the frond, the individual filaments are often threadlike 
and sometimes largely longitudinal. The more or less club-shaped 
ramuli radiate outward and are contiguous, though not united, so as 
to constitute the periphery of the frond. The fructification of Codiurn 
i.s contained in oval or ovate sporangia laterally situated near the 
bases of the ramules. It is hardh' to be expected that such sporangia, 
enshrouded by ramules, would be discernible in carbonized and com- 
pi'essed specimens except by a most favorable accident of preservation. 
The analogy between the impression of or the residual surface of the 
spongoid Bnthotrephis and the texture of Codium, is forcibly sugges- 
tive: and although the stronger, apparentl}" central, filaments {'.) of 
B. newlinl (Plate XVII, a) are (.'oarser than any to be seen in such 
specimens of the dried Codium tomentosnm as the writer has had for 
examination, the comparison of the specimens can hardly fail to raise 
the question as to whether the general structure and nature of the 
organisms are not essentially the same. In some species of Codium 
the filaments are often somewhat regularly meshed, so that the surface 
suggests a looseh" though irregularh" woven cloth-like structure. It 
is worthj^ of mention that in Udotea Lamouroux, which stands next to 
Codium in the Codiaceie., the frond bears a calcareous incrustation, while 
in Halimeda Lamouroux, another genus of the same family, we lind a 
false epidermis, though the filamentose internal composition of the 
plant is like that of the other genera of the family. 
It is not the object of this discussion to argue that the BnthotripJiin 
types under consideration are to be conclusively regarded as belong- 
ing to or, at least, as closely allied to the Codium group of the Siphon- 
ous ChlorophycecB (green alga?), or even that they are indisputably 
proven to be algte; it is to call attention to the fact that we have 
among the algse, notably in the CodioGeih, types which would seem 
calculated, under favorable circumstances of fossilization, to present 
characters of form, aspect, and carbonaceous texture similar to and 
pei-haps essentially the same as those of Bnthotrephis. The specimens 
in hand appear, so far as their characters are revealed, to conform to 
and to be admissible to the algte. there being no inherent evidence to 
the contrary.^ A reference of these forms to the sponges would there- 
'It i? possible that a slight caU-areous envelope, comparable to that of Udotea, 
might assist in presening both the form and the substance in the alga? of this group. 
