126 Mr. H. J. Carter o/t tivo HexactineUid Sponges. 



does not appear to me to be equal to my own ; so I must leave 

 them for a future generation. 



Since the above was written, I have received from Mr. T. 

 Higgins a microscopic specimen of a Hexactinellid sponge 

 purchased by the Liverpool Free Museum from Mr. Gerard, 

 and said to have been collected by Dr. Meyer in tlie Pliilip- 

 pine Islands, li is Eurete farj-eopsis, and is fellow to Dr. 

 Millar's s[)ecimen above described, as I have now ascertained 

 by an examination of the entire specimen. 



Myliusia Grayi, Bk. Proc. Zool. Soc. 1869, p. 335. 

 (PI. IX. figs. 8-17.) 



Viti-eohexactinellid. General form hemispheric ; general 

 appearance enteromorphous or cerebriform ; sessile ; consisting 

 of tortuous anastomosing tubular canals or passages separated 

 by equally tortuous labyrinthic intervals. Tubular canals or 



f)assages now terminating on the surface in round patulous or 

 ong tortuous gutter-like openings. Colour white, translucent, 

 slightly yclloAved by the presence of dried sarcode. Surface 

 of (tubular passages, both externally and internally, covered 

 with a dermal layer of small sexradiate spicules, whose hori- 

 zontal arms overlapping each other form a continuous quadri- 

 lateral meshwork. Margin of the openings of the passages on 

 the surface fringed with the spined arms of long, thin, sexra- 

 diate spicules mixed with still larger (?acerates), wdiose shafts 

 are uneven but not spined, unless it be microscopically in 

 some parts. Pores and vents not discernible, from the muti- 

 lated state of the surface. Internal or body structure of the 

 wall of the tubular passages composed of lozenge-shaped or 

 lantern-like knots of vitreous fibre applied end to end, three or 

 more layers deep, thus forming a laminate mass of trape- 

 zoids united to each other at their angles in successive rows 

 (fig. 10), with cylindrical intervals between them crossing 

 each other more or less rectangularly (fig. 10, A h) ; traversed 

 by the branches of the excretory canal-system, and when 

 fresh probably more or less divided into cavities by soft porous 

 expansions of the sarcode (now dried) bearing the ampul- 

 laceous sacs or groups of spongozoa. Spicules of two kinds, 

 viz. skeleton- and flesh-spicules. Skeleton-spicules of three 

 forms, viz. : — 1, small, sexradiate, arms not inflated at their 

 junction, atteimately pointed and thickly spined throughout, 

 about 15-1800ths inch long by ^-ISOOth inch thick at the 

 base (fig. 13) ; 2, much larger, sexradiate, the same, but with 

 the arms slightly inflated at the extremity and 30- to 100- 

 ISOOths inch long (fig. 16); 3, still much larger (?acerate 



