FROM THE FUNAFUTI ATOLL. 5 
off Tongatabu, Friendly Islands, at 18 fathoms. Brady states 
that the specimens from the latter locality lack distinctive 
characters ; those around Funafuti, not so greatly distant, being 
in first-rate preservation, may serve to strengthen his identifica- 
tion. Some of the specimens from the Funafuti lagoon found 
attached to the surface of Halimeda-joints are extremely fine and 
characteristic. 
Seeing Dr. Heckel’s statement with regard to the apparently 
dubious character of some Astrorhizide, especially Rhabdammina, 
Rhizammina, Sagenella, ete., that they “ may also belong to the 
arenaceous Keratosa (Ammoconide),” I have carefully examined 
the composition of the test of Sagenina (Sagenella), with the result 
that there appears sufficient evidence in support of the view 
taken by Dr. Brady as to its rhizopodal nature. Sections of a 
Halimeda-joint with Sagenina attached. have been made in a 
vertical direction; also the test itself has been isolated. These 
were examined under a high power, and showed this organism to 
have a finely arenaceous to subchitinous test (that is to say, 
where finely divided material 1s wanting, a thin chitinous tube is 
the result) traversed by minute inosculating canals such as are 
seen in the other arenaceous rhizopods. 
Heckel describes a form of the Keratosa, namely Ammoconia 
sagenella *, with regard to which he says: “ Very similar to this 
latter, or even identical with it, may be that form which Brady 
has figured as Sagenella frondescens.” In the description of the 
species, however, the diameter of the separate branchlets is given 
as 1-2mm. The average diameter (and it varies but little) of 
the branchlets of Sagenina frondescens is *5 mm. Further, the 
example of Ammoconia figured in the Report is quite unlike 
Sagenina in consisting of a meshwork of tubes standing erect, 
instead of being adherent at every point. The general finish of 
the tubes of Sagenina, especially at the terminal or aperturai 
points, enables one to see the affinity of this form with other 
well-known rhizopods, both arenaceous and hyaline, as Webbina 
and the adherent Ramulina cervicornis. In one part of the 
transparent test which I have examined, there is a curious stel- 
late structure reminding one of the fused spiculose base seen in 
the tissues of Alcyonarians. There is not sufficient evidence, 
however, to lead one to form any definite conclusion from this 
peculiarity of structure. 
* Report ‘ Challenger,’ vol, xxxii. pp. 30 & 31, pl. viii. figs. 5 A, 5 B. 
