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Show 1875.] StLICEO-ITBROUS SPONGES. 5G1 p. 339, plate xxiv. fig. 7,there are some very small portions of the dermal membrane on parts not represented in the figure in situ on some of the angles of the rete, in which there were fragments of extraneous spicula of various forms embedded in the sarcode ; 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 T ^ inch ; and the qnadrifurcate terminal spicula measured 5-TroTrc lxxca m 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 AQULEATA. (Plate LXII. fig. 1.) Sponge-form, dermal membrane, oscula, and pores unknown. Skeleton-primary fibres cylindrical, stout, branching, and anastomosing, furnished profusely with acutely conical spines irregularly dispersed, and with numerous long, slender defensive prickles projected 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, B.N. ?). Examined in the skeleton state. The specimen, a portion of which is represented by fig. 1, Plate LXII., 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 or inhalant 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 specimen was presented to me by m y 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* |