S2 DAWSON AND HESTDE 



ous matter with little indication of radiating arrangement. Dr. Hinde remarks as to this 

 form that "the spicules do not stand out definitely, as in the case of the hexactinellid 

 sponge spicules, but appear to be imbedded in some membrane. In two instances, 

 anchoring spicules, like those of Protospongia, project from the base of the mass. I do 

 not know of any monactiuellid sponge furnished, as these appear to have been, with 

 long anchoring spicules." 



The sponges of this genus are very rare in the Metis collections, and are obscure and 

 difficult to make out as to their details. 



Genus HALICHONDEITES, Dn. 



12. — Halichondrites confusus. S.N. 



(Fig. 23.) 





Fig. 23 — Halichondrites confusus- 

 Spicules enlarged. 



Oval or irregular masses of small simple spicules, imbedded in patches of pyrite, 

 and without any definite arragement or root spicules, may indicate the presence of a 

 halichoudroid sponge. In the best preserved specimens the spicules appear to be Macerate 

 and more slender and pointed than in the last, and they seem to be in two series, inclined 

 at a very oblique angle to each other. In some specimens elongated spaces, with well- 

 defined margins, are covered with thin films of pyrites, which may have resulted from 

 the replacement or incrustation of a mass of minute spicules, of which traces remain in 

 some places. 



It is to be observed in this connection that sponges having originally much kératose or 

 other dense animal matter would naturally aggregate in and around themselves a greater 

 quantity of pyrite than those of a more purely siliceous character. 



Miscellaneous Sponge Eemains. 



Under this head may be placed : — 



(1) Surfaces covered with a confused mass of various kinds of spiciiles, probably 

 the debris arising from the decay of numerous specimens, most of which probably belong- 

 to the species above described. 



(2) Radiating groups of robust tapering spicules, some nearly an inch in length and 

 quite thick at base. They resemble at first sight spines of Echini, but were no doubt 

 siliceous, and belonged to sponges jirobably distinct from any of the species described 

 above. The best specimen has a few small cruciform spicules at the base of the large 



