THE SPONGES OF THE WEST-CENTRAL PACIFIC 109 



The spiculation of oxeas with toxas is characteristic of Toxadoda. The 

 hastate microscleres and the abundance of protoplasm and colloid producing 

 the cheese-like consistency is not only unique in the genus Toxadoda but 

 sets this sponge so drastically aside that it may well deserve a new genus. 

 This step is, however, postponed at the present time. 



The specific name is derived from the Greek word for "cheese-like." 



There are two species which should now be transferred to the genus 

 Toxadoda. They are the ones first described as : 



Toxochalina borealis Lambe, 1894, page 15, Western Canada. 



Toxochalina robusta Ridley, 1884, page 403, East Indies. 



GENUS SIGMADOCIA de Laubenfels 

 Sigmadoda emphasis, new 



Text Figure No. 69 



This species is here represented as follows : 

 U.S.N.M. No. 23099, My No. M. 481, here designated as type, collected 

 September 1, 1949, by diver in Iwayama Bay, Koror, in the Palaus. 

 The depth was less than 2 meters, in muddy water, near mangroves ; the 

 substrate was coral fragments. This species was very common in such 

 localities in the Palaus. 



The shape is massive to amorphous, and individuals were often 4 by 6 

 by 6 cm in size. 



The color in life was dull lavender on the exterior and drab within. 

 The consistency was softly spongy, easily cut. 



The surface is distinctive. It is between coarsely velvet-like and very 

 finely conulose. It is covered with myriads of small projections, each less 

 than 1 mm high and 1 mm apart. The pores are about 250 /x in diameter 

 when alive, but very readily closed by membranes which pull across. They 

 are chiefly closed in the preserved specimens. The oscules are 4 mm in di- 

 ameter, do not close, and are very few in number. 



The ectosome is a thin, definite dermis, very full of sigmas. The endo- 

 some is isodictyal, nonfibrous, and typical of the family Adociidae. 



The skeleton consists of oxeas, often united end to end by a little 

 spongin. They range from 9 ^ by 185 ju. to 10 /u, by 205 ix in dimensions. 



P* 



r~^ 



Text Figure No. 69. Spicules of Sigmadocia emphasis, X 781. A: Two of the oxeas. 



B: Two of the sigmas. 



