524 ZOOPHYTA. SPONGIADiE. Halichondria. 



portions, especially towards the mai'gin, and produces a cracked surface when 

 drying. 



108. H. hifundibuliformis. — Widely funnel-shaped, thin, 

 uniform, and brittle ; spicula long, linear, and pointed. 



Spong. inf. Linn. Syst. i. 1296. Jameson, "VVern. Mem. 562. — Northern 

 Islands rare. 

 Body cup-shaped, when dry tender ; nearly of uniform thickness ; the 

 pores are not half the size of the preceding "species, the substance is softer, 

 and the spicula shorter and less matted. 



** Inhabiting fresh zvater. Spongilla of Lamarck. 



109. H. fluviatilis. — Soft, brittle, and slenderly fibrous when 

 dry ; spicula linear and doubly pointed. 



S. fluv. Linn. Syst. i. 1 299 — Pallas, El. 384 — S. friabilis, Grant, Edin. 



Phil. Journ. xiv. 270 — In rivers and lakes. 



Massive, with the surface rising into narrow ridges or pointed branches ; 



sometimes slenderly branched and acuminated (then constituting the S. ca- 



nalium of Gmelin ; Flem. Phil. Zool. ii. 614. t. v. f. 4.) The fibrous structure 



very obvious, the fibres fine, and diverging from the centre ; pores small. 



110. H. lacustris. — Hard, brittle, and coarsely fibrous ; spi- 

 cula linear, and doubly pointed. 



S. lac. Linn. Syst. i. 1299. Don's Animals of Forfarshire, 36. — In lakes 

 in Angus and Fife. 

 Massive, rising into short rounded branches ; the fibres are coarser, and 

 the substance denser than the preceding ; the spicula, too, though similar in 

 form, are thicker, and about one-fourth shorter. It is difficult to determine 

 the true place of the two fresh water Sponges noticed by Tlay, under the 

 titles " Spongia ramosa fluviatilis" and " Spongia fluviatilis ramosa fragilis." 

 —Syn. Stirp. 30. 



Gen. XLIV. SPONGIA. — Porous, the cartilaginous skele- 

 ton simple, or destitute of earthy spicula. 



111. S. pulchella. — Massive, irregular, consisting of finely re- 

 ticulated simple fibres. 



Sower. Brit. Misc. t. xliii — Southern and western coasts. 

 The texture is open, pervious to the light, the surface muricated by the 

 free extremities of the fibres ; these have an ascending direction, and fre- 

 quently anastomose, forming irregular meshes. 



Gen. XLV. GRANTIA. — Porous, the cartilaginous skele- 

 ton strengthened by calcareous spicula. I have ventured 

 to dedicate this genus to Dr Grant, to commemorate his 

 valuable services in elucidating the physiology of sponges, 

 already referred to. 



112. G. comprcssa. — Subtubular, compressed, with simple, 

 terminal, and lateral orih'ces ; spicula of two kinds, triradiate 

 and clavate. 



