Porifera of Friday Harbor — DE Laubenfels 
199 
Fig. 2. A, Sigmadocia edaphus de Laubenfels. 
cies. E, Choanites suberea var. lata (Lambe). 
B, Mycale adhaerens (Lambe). C, Stylissa stipitata new spe- 
The structure of the interior is very fibrous, 
the fibers themselves being plumose as seen 
under the miscroscope. They probably contain 
a small amount of spongin, but are composed 
chiefly of abundant rows of spicules, which are 
smooth styles, reaching a maximum size of 
about 10 X 320 /*. However many are as small 
as 8 X 300 /* and the smaller spicules occa- 
sionally show a tendency to be tylostylote. There 
are very numerous stout palmate anisochelas of 
three size ranges, 14 to 15/*, 27 to 28/* and 56 
to 60/*. This largest category frequently has the 
spicules associated together in symmetrical 
groupings known as rosettes. There are also 
two size ranges of sigmas, the smaller having a 
chord length of about 20/*, and the larger of 
35/*. 
This sponge may be readily distinguished in 
the field from the other Pecten -covering sponge, 
Ectyodoryx parasitica , by the very fibrous struc- 
ture of the interior of the Mycale , and the 
greater ease with which its ectosome may be 
detached from the endosome. 
This species was originally described as Es- 
perella adhaerens by Lambe (1893: 27) and 
the genus was later shown to be synonymous 
with Mycale by de Laubenfels ( 1936a: 122). 
Stylissa stipitata new species 
Fig. 1, FI, 2 C 
The holotype, USNM no. 22687, was col- 
lected near False Bay of San Juan Island. It was 
dredged at a depth of 20 m., only 100 m. off 
