1875.] SILICEO-FIBROUS SPONGES. 561 
p- 339, plate xxiv. fig. 7,there are some very small portions of the der- 
mal membrane on parts not represented in the figure zz situ on some 
of the angles of the rete, in which there were fragments of extraneous 
spicula of various forms embedded in the sareode ; but I could not 
detect any form among them that could be assigned with any degree 
of probability as belonging to that dermal membrane, while in that 
of that of the species under description the dermal membrane 
abounded with them. The form of these spinulo-quadrifurcate 
sexradiate stellate spicula is slender and very beautiful; and they 
are so numerous in some parts of the tissue, and so closely packed 
together, that their forms are completely obscured; but in other 
parts, where a few only occur, they may be frequently seen in a very 
perfect condition. They are very minute: one of the largest that 
was measured did not exceed in its extreme diameter 75, inch; 
and the quadrifurcate terminal spicula measured 5,}>55 ch in 
diameter. 
The large, simple rectangulate sexradiate interstitial spicula with 
spinous radii, a few of which are entangled in the inner surface of 
the dermal rete, also form efficient specific characters, none such 
having hitherto been found in Farrea occa. 
Farrea ACULEATA. (Plate LXII. fig. 1.) 
Sponge—form, dermal membrane, oscula, and pores unknown. 
Skeleton—primary fibres cylindrical, stout, branching, and anasto- 
mosing, furnished profusely with acutely conical spines irregularly 
dispersed, and with numerous long, slender defensive prickles pro- 
jected in various directions, covered with minute spines, and also 
with numerous rectangulate sexradiate defensive organs, radii 
slender, entirely spinous; canals very slender, confluent, frequently 
obsolete. Secondary fibres the same as the primary ones, short and 
less in diameter. 
Colour, in the dried state, dark amber? 
Hab. West Indies (Captain Hunter, R.N.7). 
Examined in the skeleton state. 
The specimen, a portion of which is represented by fig. 1, Plate 
LXIL., is 10 lines long, by 6)wide. It has apparently formed part of 
a rather large-sized cup sponge. From the flatness of the specimen 
and the uniformity of the two surfaces, it cannot be determined with 
certainty which of the two was the outer orinhalant one; but I am 
inclined to believe that the figure represents a part of the outer 
surface ; nor can its locality be accurately determined. The speci- 
men was presented to me by my late friend Mr. Henry Deane, with 
* several other siliceo-fibrous ones, including those from the West 
Indies collected by Captain Hunter, R.N.; and I am strongly inclined 
to believe the locality to be the same as that of Farrea Gassioti, lat, 
14° 8! N., long. 77° 38! W., West Indies, 800 to 1000 fathoms. 
The reticular skeleton of this species is very regular, by far the 
greatest number of the areas being square, and the fibres in both 
directions being of about the same diameter, There appears gene- 
36* 
