136 
or arrangement, but there is one principal branch which gives rise, by 
numerous bifurcations, to nearly all the lateral branches. All the branches 
are united by very thin cross-bars, of which the direction and distances from 
each other are very irregular, but the fenestrules are generally longer than 
wide. The cells which border them generally number six on each side, and 
are easily distinguished by their marginal enlargement. The posterior 
surface is unknown to me. 
Dimensions . — The only specimen of this species known to me is three 
centimetres long, by about one and a half centimetres broad. The filiform 
branches are about one millimetre apart. 
Delations and Differences species is very like D. undulata, 
J. Phillips, from which it differs essentially only by the number of its 
cells. J. D. Dana compares the species described by him with the F. formosa, 
McCoy, which is easily distinguished by the pores with which the median 
keels of the branches are pierced. 
Horizon and Localities. — It accompanies the preceding species. J. D. 
Dana found it at Glendon, New South Wales. 
Genus — PROTORETEPOEA, L. G. de Koninch} 
The coenoecium is infundibuliform, composed of numerous coalescing 
branches, generally bifurcating several times before reaching their complete 
development, and radiating from the thin peduncle, which forms their start- 
ing point. By this radiating arrangement the branches give rise to regular 
rows of little holes, or fenestrules, oval in outline, which are regular in their 
course, and parallel. The whole internal surface is covered with numerous 
rows of small cells, generally arranged quincuncially. The surface is almost 
smooth, or covered with a large number of fine scarcely visible longitudinal 
striae. 
Delations and Differences. — This genus, of which F. ampla, Lons- 
dale, may be considered the type, has been created for a certain number of 
Palaeozoic Bryozoa, which, in general form, bear some resemblance to species 
of the genus Detepora, found in Tertiary rocks, and alive in our present seas. 
It is, however, very easy to distinguish them from each other, because, in the 
1 IVide Etheridge, R. Junr., Geol. and Pal. Q’land, 1892, pp. 219-222.] 
