126 ZOOLOGICAL COLLECTIONS MADE DURING [Jan. 4, 



Reniera fortior, Schmidt? (Plate XI. fig. 3.) 



Renier a fortiori O. Schmidt, Spong. atl. Geb. p. 40. 



A poorly preserved spirit-specimen, which has lost most of the 

 dermal membrane and much of the internal sarcode. 



Examined. In spirit and by momiting in balsam. 



External Characters. Form massive, irregular, subglobose, at- 

 tached by a short pedicel about one fourth as broad as the greatest 

 diameter of the Sponge. Texture very elastic. Colour semitrans- 

 parent dirty white ; surface in present state chiefly regularly and 

 minutely hirsute. 



Minute Surface-characters. Where the dermal membrane is pre- 

 sent, this consists of a very thin brownish-yellow lamina, resting on 

 the ends of the primary skeleton-columns, and formed by a skele- 

 ton network of 1- to 2-serial lines of fine acerate spicules, lying in a 

 fine fibre, with meshes of 1| to 2 spicules' lengths in width, crossing 

 each other at acute angles, the intervals being more or less occupied 

 by fine and stouter acerates lying in the almost transparent, slightly 

 granular sarcode which fills them. Where this membrane is absent, 

 the ends of the skeleton-columns project as fine pencils. 



Vents 1 apparently represented by 4 or 5 roundish apertures, 

 of about 1 millim. diameter each, situated on a somewhat concave 

 lateral surface ; they appear to lead directly inwards. 



Pores 1 apparently scattered or aggregated in twos, oval ; largest 

 diameter '045 millim. 



Main Skeleton. Composed, in the older parts, of Chahnoid fibre, 

 containing only about half its hulk of horny matter ; in the younger 

 parts a margin of this material is but rarely seen to surround the 

 spicular axis; possibly this is partly due to imperfect preservation. 

 Colour absent, or of the faintish possible tinge of yellow. Primary 

 fibres contain a 2- to 4-, generally 3-serial axis of moderately 

 stout, short acerate spicula ; they run from the centre to the sur- 

 face, meeting the latter approximately at right angles, and are distant 

 from each other by 2 to 4 spicule-lengths. Secondary fibres at right 

 angles to the primaries, usually composed of a double series of iden- 

 tical spicules ; occur at intervals of 2 to 3 spicule-lengths. 



Sl-eleton-sjiicules. Of one form — short stout acerate, slightly and 

 gradually bent, or with a slight angle, tapering gradually to the 

 points; size -13935 miUim. long by -0094 broad. 



Flesh- and Dermal Spicules. Of one form — short slender acerate, 

 slightly and gradually bent, tapering gradually to points ; size of 

 average largest '10135 ipillim. long by '0038 broad, in the case of 

 the dermal, '1077 long by '006334 broad, in the case of the flesh- 

 spicules, which latter are probably merely young skeleton-forms. 



Hab. Elizabeth Island, Straits of Magellan (eastern portion), 

 sandy bottom, 6 fathoms. 



Chalina granti, Bowerbank, strongly resembles this Sponge in its 

 chief essential characters ; the main differences between the two are 

 those of degree rather than of kind. Thus the skeleton-spicule mea- 

 sures •133 by -01056 millim., and is of the same type of acerate, 

 though, as the measurements show, it is, although shorter, actually 



