508 HYATT'S REVISION OF THE 



In describing the species of this genus I have made comparisons between three principal 

 Mediterranean, and three of the American commercial sponges, in order to show the very 

 evident relationship of these forms. Schmidt describes five Mediterranean species in all, 

 and may be right ; but so far as I can understand his descriptions, with the aid of a fine 

 collection of specimens purchased by Prof Baird for the National Musemn, from Mr. Isaacs 

 of New York, I cannot make more than three out of the ordinary commercial varieties, 

 which were fully represented and appeared to include the entire range of his five species. 

 Von Eckhel's work upon the " Badeschwamme," although a purely commercial treatise, has 

 the same view of the affinities of the sponges, based upon the observations of tlie fish- 

 ermen and dealers, and the distribution of the sj^ecies ; the latter is quite remarkable. 

 Only one species, the Sjiongia officinalis Linn., Adriatica Schm., is found on the eastern 

 shore of the Adriatic and coast of Greece, from Trieste to the Bay of Nauplia. From 

 Nauplia and the island of Candia to Eritra, on the coast of Asia Minoi', two occur, Spongia 

 officinalis and Spongia agaricina Pall., Zimocca Schm. From Eritra, opposite the island 

 of Chios, to Tripoli, all three, Spongia officinalis, agaricina and equina, are fished, except 

 at the island of Cyprus, where the Zimocca sponge does not live. From Tripoli to Tunis 

 two only occur, Spongia officinalis and equina, and from thence to Ceuta at the Straits of 

 Gibraltar, a very peculiar, dark colored and coarse variety of the Sj)ongia equina is ob- 

 tained, called the Gerbis sponge. 



This distribution indicates the naturalness of the three species, and shows also that the 

 dealers have to do with a vast variety of forms. They can, however, pick out the three 

 species and their varieties without hesitation, and I was amused and interested at finding 

 that the method pursued was precisely similar to that which I had been obliged to adopt 

 in distinguishing empirically the various sub-species and s^DCcies of Spongia. They are led 

 mainly by the general aspect of the surface. This has a distinct ajjpearance in every 

 species, and though much altered by the greater or less development of superficial tufts, 

 is much more constant than any other character. This is due to the fact that the surface 

 takes its aspect largely from the number, distribution and size of the pores, cloacal orifices, 

 superficial canals and primary fibres. These characteristics, of course, are directly correllated 

 with all that is important in the internal anatomy of the animal, amd should therefore be 

 moi-e constant than the length, form or composition of the tufts of fibres, or the shape of 

 the whole, which are capable of great modification, according to the locality in which the 

 specimen may be found. The forms of Sp>ongia officinalis may vary from cup-shaped to 

 fistular, and to irregular or lump-like. The latter are usually coarser and looser in texture, 

 the superficial tufts are longer and more numerous, and they approximate moi'e closely to 

 the coarser varieties of sub-species tubulifera of the Carribean Sea in the external aspect of 

 the surface and the apertion of the interior, than the finer varieties. 



The texture of the poorest variety of the Mediterranean sponges is, however, always 

 better for domestic purposes than the best of the corresponding American varieties, being- 

 firmer and more elastic ; and it is also to be remarked, that the last never have the cup- 

 shape, which is so common in the sub-species J/ecZi^e/Tcoiea, and that the fistular form takes 

 its place. The forms of Sp)ongia agaricina, sub-species Zimocca, vary from saucer-shaped 

 to irregular lump-like growths. As in the Sjwngia officinalis, it may be shown that these 

 aberrant forms ai'e quite similar to the aberrant or formless varieties of the sub-species imnc- 

 tata of Florida, as regards the aspect of the surllice ; but these also are nevertheless nuich 



