Solenogaster Mollusks — Schwabl 
271 
tion of fore- and mid-gut. Buccal glands and 
lateral and dorsal salivary glands are present. 
The radula has one pair of sickle-like teeth, one 
pair of small lateral teeth, and an unpaired 
piece. The mid-gut bears a cuticular stripe 
dorsally. The liver has granular cells which are 
present also at the end of the irregular septa. 
Gill lamellae number 15-20. The heart is mus- 
cular and has two atrioventricular openings. 
DISTRIBUTION : This species occurs commonly 
in the San Pedro area of southern California, 
in depths of 330-1100 m, in sediments of mud 
or clay. It is frequently found in glass sponge 
associations. 
Crystallophrisson nanulum (Heath) 1911 
Fig. 13 
Chaeto derma nanula Heath, 1911, pp. 66-67, 
pi. 4, figs. 1, 12, pi. 27, fig. 3, pi. 28, figs. 
7, 10, 11, 12, pi. 37, fig. 18. 
COLLECTIONS: 
2220 (7) in 180 fm, with C. hartmani and 
Limifossor fratula. 
2221 (2) in 147 fm, with Limifossor fratula. 
2361 (2 ) in 167 fm, with Limifossor fratula, 
C. hartmani and C. sp. 
Fig. 14. Crystallophrisson hancocki. Characteristic 
spicules from body regions c and d. 
2612 (1) in 100 fm, with Limifossor fratula 
and C. sp. 
2625 (1) in 230 fm, with Limifossor fratula 
and C. hartmani. 
DIAGNOSIS: The body is small, comparatively 
stout (Fig. 13), and measures 7-9 mm long 
and up to 1.2 mm at its greatest width. The 
spines are keeled and appear heavy. The color 
of the body is yellowish-brown. The radula 
is small and has two small denticles. Salivary 
glands are reduced to a small group of cells 
near the radula. 
DISTRIBUTION: This was originally described 
based on a single specimen from southern Cali- 
fornia, in 260-284 fm. The present collections 
include 13 specimens, all from the San Pedro 
area, in depths of 100-230 fm, and always as- 
sociated with Limifossor fratula in sediments of 
green or sandy mud. 
Fig. 13. Crystallophrisson nanulum. Sta. 2220. 
