124 



THE SPONGES OF THE WEST-CENTRAL PACIFIC 



Hiattrochota baculifera (Ridley) de Laubenfels 



Text Figure No. 77 



This species is here represented by the following : 

 U.S.N.M. No. 22923, My No. M. 229, here designated as type, collected 

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

 The depth was 2 meters, and the substrate was dead coral. 



The shape is thinly incrusting or, in some cases, a mass full of coarse 

 coral. Of the latter, it may be regarded that the large coral particles are 

 thinly incrusted and held together by sponge tissue. Because of this peculiar 

 structure, it is difficult to give dimensions for this species as found in the 

 Palaus. 



The exterior and interior color in life was purplish-black or blackish- 

 purple. There was no green wash over the surface, but the specimens did 

 bleed a rich purple exudate when handled. The consistency was colloidal with 

 obviously stiffly spongy fibers present. 



The surface is conulose with conules 2 mm high and 2 to 5 mm apart. 

 The pores and oscules cannot be discerned. 



The ectosome consists of a thin dermis, protoplasmic in nature, about 

 10 ii thick. The endosome is softly colloidal with a loose irregular reticula- 

 tion of spongin fibers. 



The skeleton, while fibrous, is so irregular that dimensions of the fibers 

 cannot readily be given. The spicules consist of smooth strongyles, chiefly 

 in the ectosome, 5 ii by 250 ti in dimensions, and smooth styles, chiefly in 

 the endosome, 11 ii by 195 /a. The microscleres are birotulates, 14 ll to 16 /x 

 in length, and apparently have just 4 clads at each end, no more. 



This species was first described as Iotrochota baculifera by Ridley, 1884, 

 page 435, from the Indian Ocean and the Australian region in general. 

 Thiele, 1899, page 18, extended its range into the East Indian area. It is 

 here for the first time transferred into the genus Hiattrochota. 



A C 



J- 



<S=f> C (S=i> 



Text Figure No. 77. Spicules of Haittrochota baculifera, X 781. A: Strongyle from the 

 ectosome. B: Style from the endosome. C: Amphidisc microscleres. 



