TOL. LX.] PHILOSOPHICAL TRANSACTIONS. 33 



tubes, growing together into a mass, all assurgent, and of which some of the 

 larger appear pyxidated like a calyx, with a bifid and trifid base, and furnished 

 with two or three columns; the smaller tubes are shaped like a mouse's tail, end- 

 ing in a rounded point. The body or substance consists of a tough or but 

 slightly compressible substance, of a deep dusky colour. It is found on the 

 Etrurian coast, from Populonia, in a place called Porto Baratto, and is not very 

 common. It admits of a great many varieties, some with the tubes completely 

 conoid as it were, upright, oblique, here and there inverse, with an entire base, 

 sometimes perforated or pervious with holes. "' 



Fig. 3. Stupose, tuberculated sponge, with simple and branched tubercles, 

 but with the ramiiications imperfect, and commonly obtruncate at the roots: the 

 form of the mass is subconoid, flattish at the top, the whole surface unequal, 

 every where rough with branches and tubercles, hollowed and bifid at the base. 

 The body consists of a tough substance, considerably anfractuous within, with 

 some of the cavities wider or more excavated than the rest : its colour is dusky. 

 It is found on the Etrurian coast, not far from the mouth of the river called la 

 Cornia. This sponge, rising from a wide and hollowed base, terminates in a 

 subconoid, flattened head, not ill resembling the shape of a mitre. It is called 

 the Pope's Mitre by the Neapolitan fishermen, being common about the coast 

 of Naples. An Alcyonium durum, presbyterorum pilpolum prorsus effingens. Cu~ 

 pani Hort. Cathol. Suppl. 1.? 



Fig. 4. A very small sponge, of an inversely conoideal shape, and twisted 

 like a worm. It consists of a very dense and tough substance, with the fibres 

 closely cohering together as in the Spongia hircina : its colour is dull brown: 

 These sponges are found closely adhering in groupes to stones, shells, and other 

 marine bodies. This is a very rare species of sponge, and had not, so far as he 

 knew, been either figured or described. Count Marsigli long ago described 

 something analogous to it under the name of Eperon de Coq.* It differs how- 

 ever from the present species both in colour, and in having a pyxidated head, as 

 appears from the figure. He had observed some solitary specimens of the present 

 species of sponge on the Etrurian coast, between Populonia and the mouth of 

 the river Cecina. One very perfect specimen he observed in the Museum of 

 Signior Philip Fabrini, near Pisa, and which was fished out of the Tuscan sea. 



Fig. 4 and 5 show a congeries of this sponge growing on a calcarious stone, 

 and also a detached single specimen. 



It is well known, from the observations of Mercati, Boccone, Donati, and 

 others, that the coasts of Italy in general afford a remarkable variety of zoo- 

 phytes. Pallas likewise particularly mentions the many species of gorgoniae 



* Hist. Phys. de la Mer, part ^, p. 63, pi- 5, n. 22. 

 VOL. XIII. F 



