Sponges of Palau, I— BERGQUIST 
100 // 
1 10 u \ 
Fig. 33 b. T 'etilla- microxea n. sp. Spicules: 1, Oxeas. 2, 
197 
the cladome head just below the sponge surface. 
Micros cleres. (a) Microxeas, fine, spindle- 
shaped spicules which are distributed tangen- 
tially in the dermis and in confusion in the 
endosome. (b) Sigmaspirae of typical tetillid 
form but apparently quite smooth. 
Spicule dimensions ( in p ) . 
Oxeas: 587- (2000) -2875 X 4- (30) -50. 
Anatriaenes: at least 3400 X 3-8 (all spicules 
incomplete), cladome 33. Protriaenes: 3125 X 
8.5 cladi, 16-40 X 2. 5-3. 5, cladome 13-50. 
Microxeas: 150- ( 184)-230 X 1.5- ( 2.3 ) -3.5. 
Sigmas: 10- (18) -32. 
histology: The ectosome is not a clearly 
differentiated region; the dermis is a slightly 
collenchymatous, lightly pigmented layer which 
grades imperceptibly into the endosomal sar- 
chenchyma. 
discussion: Tetilla microxea can be com- 
pared with Tetilla monodi Burton from West 
Africa and Tetilla oxeata Burton from south 
Arabia. These three species are, as far as can 
be ascertained, the only other members of this 
genus which possess small oxeas and have them 
scattered throughout the sponge rather than 
arranged in a definite cortical layer. Tetilla 
