OCR Text |
Show 1867.] DR. J. E. GRAY ON SPONGES. 497 Dr. Oscar Schmidt gives the following synoptic.d table of his genera of Ceraospongice :- I. With only one kind of elongated, homogeneous, horny filaments. Filament very elastic, difficult to split, and very variable in thickness SPONGIA. Filament slightly elastic, of unequal thickness .... CACOSPONGIA. Filament scarcely at all elastic, extremely brittle when dry SPONGELIA. II. With only one kind of elongated, non-homogeneous filaments. The bark and axial substance of the filaments different APLYSINA. III. With two kinds of horny filaments. The second kind forming a superficial network .... DITELLA. The second kind terminating in a little head. Tissue of the finer filaments loose HERCINIA. Tissue of the finer filaments dense SARCOTRAGUS. The Halichondria; he divides into genera thus:- I. The firm horny substance evident, surrounding the spicules. The whole sponge-body uniform, horny, and spicular. Branches numerous, anastomosing CLATHRIA. Branches slender, not anastomosing RASPALIA. Part of the sponge horny and part crustaceous. Sponge crustaceous ; the horny substance forming irregular processes SCOPALINA. Sponge branching; the horny substance only in the axis AXINELLA. II. The horny substance none, or little evident. The inhaling-pores in sieve-like groups CRIBRELLA. The inhaling-pores scattered. Oscules on peculiar papilla PAPILLINA. Oscules various. Skin-clothing very obvious, and alone pigmented .. A C A N T H E L I A. Skin-clothing when present without pigment, or with the parenchyma alone pigmented. Spicules or needles blunt at the end, and generally knobbed, with special hook-shaped corpuscles .. ESPERIA. Spicules or needles blunt at the end, and generally knobbed, without hook-shaped corpuscles SUBERITES. Spicules or needles very simple, generally with both ends pointed RENIERI. Spicules or needles smooth and nodose, mucous, gelatinous MYXILLA. Boring into limestone or shell VIOA, PROC. ZOOL. Soc-1867, No. XXXII. |