STUDIES ON THE COMPAEATIVE ANATOMY OF SPONGES. o 



lected by Mr. Wilson, and preserved in ordinary niethylated 

 spirit. This was supplemented by some fragments taken from 

 a fresh specimen by myself when out dredging with Mr. Wilson, 

 and preserved in absolute alcohol, and by three young examples 

 of great interest. Sections were cut in different directions by 

 hand, by the freezing microtome, and by the paraffin method. 

 For studying the skeleton, hand-cut sections of unstained ma- 

 terial and preparations of the spicules boiled out with caustic 

 potash are most serviceable. For minute anatomical and his- 

 tological work, thinner sections of material stained with borax 

 carmine, and cut by the ordinary paraffin method, were found 

 to yield good results. 



The Anatomy of Grantia labyrinthica. 



(a) Historical. 



The sponge under consideration was, as I have stated above, 

 originally described by Mr. Carter in the 'Annals and Maga- 

 zine of Natural History ' in 1878 (3), apparently from a dry 

 and imperfect specimen in the British Museum collection. 

 The brief description is confined almost entirely to the ske- 

 leton and the external characters, but the author observes that 

 " in spiculation and in the structure of the lamina it is 

 closely allied to Grantia compressa, Fleming." He refers 

 the sponge, however, as already noted, to his genus 

 Teichonella. 



In 1886 Mr. Carter was able (1) to supplement his original 

 description from the examination of specimens dredged and 

 sent to England by Mr. Bracebridge Wilson. He observes 

 that ''the sponge is goblet-shaped in general form, and not 

 simply 'vallate,^ likeT. prolifera; also that a quadri radiate 

 forms part of its spiculation ; hence these additional facts 

 render it necessary that it should be relegated to the vicinity 

 of Grantia compressa, where its generic name might be 

 changed from 'Teichonella ' to ' Grantia.'^' 



Previously to this date, however, Mr. Carter had published 

 in the ' Annals and Magazine of Natural History ' a remark- 



