782 G. J, HINDE ON SOME FOSSIL CALCISPONGES FROM 
sinuous bands from ‘06 to °125 millim. in width; the spicular 
structure is but obscurely shown, but it appears to correspond with 
that of the preceding species. 
This form mainly differs from B. cristata in having the upper 
surface either smooth or showing mere traces of projecting ridges ; 
the fibres also appear to be somewhat more closely arranged. Only. 
a single specimen of this minute species was available for a thin 
section, and consequently but a very small surface of the fibre is 
shown; but although the structure is largely obliterated, spicular 
rays can be distinctly seen. The matrix in the specimen examined 
is partially composed of iron pyrites. 
Distribution. Jurassic: Richmond, Surrey, 1205 feet beneath the 
surface. . 
OcuLosponera MinvTA, Hinde, n. sp. Plate XXXYV. figs. 5, 5a, b. 
Sponges small, irregular in outline, apparently free. The upper 
surface is convex and exhibits an open mesh-work of fibres with 
sparsely scattered circular apertures of oscules, about *75 millim. in 
width. ‘The base is concave and covered with a compact wrinkled 
dermal layer. An average specimen measures 7 millim. in width 
by 5 in height. 
In a microscopic section the fibres appear as loosely disposed 
sinuous bands from :08 to 1°6 millim. in thickness, composed for the 
most part of three-rayed spicules with their rays in the axial part 
of the fibre. Only fragments of the larger spicules are recognizable, 
but it is probable that these were surrounded by smaller spicules, 
as in Sestrostomella. Faint markings of spicules can be seen in the 
dermal layer. 
The minute dimensions of the sponge itself and of the oscular 
canals characterize this species. 
Distribution. Jurassic: Richmond, Surrey, 1205 feet beneath the 
surface. 
Although from the fact that all the forms discovered represent 
new species, no decisive conclusion can be drawn as to the cor- 
relative age of the stratum in which they occur, yet the general 
facies of these sponges approximates closer to Jurassic than to 
Cretaceous forms. Of the four genera represented, Blastinia and 
Inobolia are exclusively Jurassic, whilst the other two, Peronella and 
Oculospongia, are partly Jurassic and partly Cretaceous. It is true that 
no great importance can be attached to the evidence of these sponges 
as to the relative position of the stratum in which they occur, but 
from the fact that Blastinia cristata is closely allied to a sponge 
from the middle Jura-Kalk of Streitberg, and that Inobolia macula 
is referred to a genus hitherto only known from the Inferior Oolite 
of this country, it is probable that they belong rather to the middle 
or lower portions of the Oolitic series than to the upper. 
The presence of calcareous sponges may be taken, as a rule, to 
indicate that the beds in which they occur have been deposited in 
comparatively shallow water. That this rule, however, is not 
