378 ^Ir. r. llii::iriii on a new IlexactinelUd 



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on the head of the chisel, the handle being represented 

 by a twisted ro))e-like anchoring appendage. The colour is 

 light sponge-yellow. The dennal suiface, now entire only 

 on the lower half of the sponge, consists of a latticework, 

 generally of a light grey colour, following the gentle undu- 

 lations of the exterior of the mass, and is entirely " pore- 

 area." There are no "vent-ridges" as in Meyerina chtra-- 

 formis ; but at the top of the sponge is an irregular fuiniel- 

 shaped cloacal oritice communicating with cavities in the 

 centre of the mass. The glass-rope-like anchoring appen- 

 dage has been imbedded for half its length in the sandy 

 bottom of the sea, has a strong spiral twist, issues from the 

 sponge as a cord, and, cord-like, ])asses up through fully two 

 thirds of the head. The latticework of the surface is covered 

 by a sarcodic investing membrane, pierced with pores over 

 the interstices, which pores are bordered by the arms of a little, 

 dermal spicule (to be more particularly described hereafter) 

 whose points touch each other, thus forming a lesser lattice- 

 work within the interstices of the larger one. The pores tlius 

 situated lead at once into the general canal-system, which 

 consists of very large and small passages, usually with rather 

 thin walls, and having an areolar appearance. Some of the 

 large canals take a vertical course towards the depression at 

 the top of the sponge ; others run directly across it into the 

 central cavities ; but all communicate directly or indirectly 

 with these cavities — which arc more or less ovate in form, and 

 extend up and down the sponge round the cord or fixed end 

 of the anchoring rope. 



The spicules composing the glass rope are of one kind only, 

 12 to 14 inches long, and fusiform. The fixed end of this spicule 

 or that part Avithin the sponge, is smooth j and the surface of 

 the free portion is also smooth i'or half or tAvo thirds of its ujjper 

 part ; biit after this it begins gradually to present what a})pears 

 to be a broken spiral line, which by degrees becomes wider. 

 Soon the line becomes a ledge, the perpendicular margin of 

 which looks towards the sponge; and on the ledges are found 

 thin pointed flat s])ines or teeth standing up side by side 

 in a row or line. ]5y degrees the ledges carrying many teeth 

 subside into brackets carrying a single s])ine only, when 

 the spicule has an undulating or sinuous aj)pearanec for a 

 short distance and finally a short, smooth, straight portion, 

 Avhen, having reached its greatest amount of attenuation (viz. 

 about l-400th of an inch in diameter), it again gradually SAvells 

 out to l-300th of an inch, and then ends in a small, thick, 

 conical or milre-shajjcd head, with four short round arms,, 

 recurved and ojipositc or at right angles to each other, the 



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