Sponges of Hawaii — De Laubenfels 
The skeleton consists of strongyles, 3 by 
210 to 3 by 240/x, and normally shaped arcuate 
chelas l6g long. 
The genus Xytopsiphum appears to be con- 
fined to the Hawaiian Islands; the type, X. 
kaneohe de Laubenfels, was described from 
Oahu by de Laubenfels (1950: 12). This Oahu 
species is characterized by slightly smaller 
megascleres (which is trivial) and by chelas 
radically different from those of the present 
species. The chelas of the former, while 
technically arcuate, are U-shaped with thick 
shafts and minute clads. The new species, 
meganese, is set off by having normal chelas 
with thin shafts and well- developed clads. 
( g Tj ! 
Fig. 4. Xytopsiphum meganese: spicules, from camera 
lucida drawings; one of the strongyles and three views 
of the arcuate chelas. (The scale shows 100 microns 
by tens.) 
The name which is here selected is derived 
from the Greek words for "large” and 
"island,” indicating that it is the species 
which is characteristic of the large island of 
Hawaii. 
Callyspongia diffusa (Ridley) Burton 
Described in de Laubenfels (1950: 12). 
This species appears to be moderately com- 
mon throughout the Hawaiian Islands. Hiatt 
found it at Halape in 1945. I found it at 
Kaalualu in 1948. 
Damiriana hawaiiana de Laubenfels 
Described in de Laubenfels (1950: 14). 
This species appears to be moderately com- 
mon throughout the Hawaiian Islands. Hiatt 
found it at Halape in 1945. I found it at 
Kailua in 1948. 
Toxadocia violacea de Laubenfels 
Described in de Laubenfels (1950: 14). 
This species appears to be moderately com- 
mon throughout the Hawaiian Islands. I 
259 
found it not only on Oahu, but also near 
Hilo in 1948. 
Petrosia puna new species 
Fig. 5 
The type specimen of this species is U. S, 
National Museum, Register Number 22780 
(My No. H. 72; Halape No. 1-106), collected 
in August, 1945, by Hiatt at Halape. It was 
said to be abundant on the undersides of 
stones at the seaward edge of a rocky shore 
at depths less than 1 meter. 
This sponge is an incrustation, pale drab in 
life, of hard consistency. There is a tendency 
for its dermal spicules to be tangentially 
arranged. The endosome is densely packed 
with spicules and is only microcavernous. 
There is no localization of the different kinds 
of spicules. 
The skeleton consists of megascleres of 
two size ranges. The larger type may be oxeas 
13 by 166 styles 14 by 132 ju, or strongyles 
13 by 135 m; each of the three occurs in ap- 
proximately equal abundance. The size range 
of smaller spicules, almost as abundant as the 
larger, consists entirely of oxeas about 4 by 
96 M. 
Fig. 5 . Petrosia puna: spicules, from camera lucida 
drawings. A, Strongyle; B, style; C, oxea, larger size; 
D, two of the smaller oxeas. (The scale shows 100 
microns by tens.) 
This new species exhibits many points of 
difference from all others in the genus 
Petrosia except the genotype, which was first 
described as Reniera dura by Schmidt (1862: 
77). This species, dura^ is so far recorded only 
from the Mediterranean. From it the new 
