74 THE DISCOVERERS 



5. " Orbicular ; such as are globose, with internal, radiat- 

 ing, asbestine spicula." 



38. Spongia verrucosaf 39. Spongia pilosa. * 



Dr Grant, in the course of his researches, detected three 

 species on the Scottish shores not included in this copious 

 list : viz. Sp. sanr/uinea, cinerea, and seriata. 



The attention of the Rev. Dr Fleming seems to have 

 been early directed to this family of organized beings. 

 Montagu has acknowledged the assistance derived from 

 him, and three of the species, \\z. Sp. complicata, scypha,and 

 pilosa, are introduced into his Essay upon Fleming's sole au- 

 thority. Availing himself of the discoveries and suggestions 

 of Dr Grant, Dr Fleming made a happy improvement in 

 the classification of sponges, which had been previously se- 

 parated into genera on characters of trivial importance and 

 confessed instability, such, for example, as their shapes or 

 degrees of porosity. " The axis," says Dr Grant, " differs 

 so entirely in its nature in different sponges, that the living 

 properties observed in one species, ought with very great 

 caution to be extended to any other, and natm'alists may 

 probably take advantage of this difference in classifying or 

 subdividing this numerous and obscure tribe, "f This was 

 written in 1826 ; and in 1828 Dr Fleming carried the hint 

 into execution. To such as have their axis or skeleton com- 

 posed of horny tubular fibres only he restricted the name of 

 Spongia ; he gave the name of Grantia to those whose ske- 

 leton consists of calcareous spicula ; and that of Halichon- 



* The species to which the character f is affixed had been previously 

 ascertained to be indigenous. 



t Edin. Phil. Journ. xiv. p. 339. 

 3 



