SPONGES OP THE OEDEB ECHINONEMATA. 



495 



the shape of corals of the genus Turbinaria, viz. an open cup ; 

 its short pedicel measures about 2| inches in maximum diameter. 



Maximum diameter of cup about 12 inches, height 7 inches ; 

 thickness of wall near edge | to \ inch (6 to 12 mm.). It is at- 

 tached to the upper valve of a pearl-oyster (Avicula margaritifera), 

 which was evidently alive when taken from the sea, in spite of 

 the presence of its bulky messmate. 



The occurrence of a third specimen is certified by a slide of 

 spicules in the Museum collection, which, as it was presented by 

 Mr. G-. Clifton, to whom the Bowerbankian collection of foreign 

 Sponges owes an immense series of very fine specimens from 

 Fremantle, S.W. Australia, probably was made from a sponge 

 obtained in that region. 



As the Museum has been fortunate enough to obtain (owing 

 to the liberality of M. E. Perrier, of the Museum at the Jardin 

 des Plantes, Paris) a fragment of Lamarck's original type speci- 

 men, I am enabled to give a comparative Table of some of the 

 chief characters of these three specimens, which will afford some 

 idea of the range of variation within the species. 



Echinodictyum bila- 



Type, " Southern 



B.M. spec, N.W. 



Mr. Clifton's spec, 



mellatum. 



Ocean." 



Australia. 



W. Australia? 



External form 



Infundibular at base, 



Infundibular, one 



? 





edges prolonged 



side prolonged as 







into two lamellae. 



an everted lip. 







Outer surface 



Outer surface 







roughened ("scro- 



roughened (" scro- 

 biculated "). 







biculated "). 





Vents 



On inner surface 

 1 or more mm. in 



On inner surface 

 1 to 3 mm. in 



? 







diam. 



diam. 





Colour in dry state : 



Paleyellowishbrown. 



Pale yellowish brown. 



? 



Primary skeleton- 



6 to 10 spicules 



8 to 15 spicules 



? 



fibre (inner sur- 



thick. 



thick. 





face of sponge) : , 









Secondary skeleton- 



6 to 10 spicules 



8 to 15 spicules 



? 



fibre : 



thick. 



thick. 





Length of primary 



•21 to "28 mm. 



•28 to -43 mm. 



? 



fibre between the 









secondaries (inner 









surface of sponge) : 









Large smooth ace- 



•266 by -014 mm. 



Shape as in type. 



Shape as in type. 



rate spicule : 





•304 by -014 mm. 



•3167 by -014 mm. 



Smaller smooth ace- 



■19 by -01268 mm. 



Bather moreabrupt- 



Rather more abrupt- 



rate: 





ly pointed than in 



ly pointed than in 







type. -2216 by 



type. -2534 by 







•011 mm. 



•01268 mm. 



Spined cylindrical... 



Spines least nume- 



Shape &c. as in type. 



Spines coarser and 





rous just above 



■114 by -0095 mm. 



equally distributed 





base, -108 by '0095 





all over. '108 by 





mm. 





•01268 mm. 



