18 PLATR vitr. 



In plate i, figs. 15, 17, 20, and 21 represent varieties 

 in form of tlie skeleton spicula. 



In plate ii, figs. 45 and 46 represent varieties of 

 form of tlie connecting spicula. 



In plate vi, figs. 158 and 159, the stellate retentive 

 spicula are represented, with a power of 660 linear. 



Plate iv, fig. 93, represents one of the tuberculated, 

 fusiformi-cylindrical retentive spicula. X 660 linear. 



EciONEMiA PONDEEOSA, Bowerhank. 



Vol. ii, p. 56, ' Mon. Brit. Spongiada3.' 



Fig. 8. — E. ponderosa, in the dried state, from the 

 type-specimen in the cabinet of the Rev. A. M. Norman. 

 Natural size. 



Fig. 9. — One of the skeleton spicula of E. ponderosa. 

 X 80 linear. 



Fig. 10. — One of the furcated attenuato-expando- 

 ternate connecting spicula. X 80 linear. 



Fig. 11. — A direct view of the apex of one of the 

 same spicula, showing the broad and strong proportions 

 of its structure. X 80 linear. 



Figs. 12, 13.— Two of the small attenuato-stellate, 

 retentive spicula. X 666 linear. These spicula vary to 

 a very considerable extent in size. 



Fig. 14. — Two of the minute, elongo-stellate, reten- 

 tive spicula. X 666 linear. These spicula are also very 

 variable in size. 



Fig. 15.- — Two of the doliolate, cylindrical spicula. 

 X 123 Hnear. 



