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PACIFIC SCIENCE, Vol. XVII, July 1963 
Fig. 12. Crystallophrisson hartmani. Left, Sta. 2302-53- Right, Sta. 2644-54. 
2362 (1) in 352 fm, with Limifossor fratula. 
2410 ( 1 ) in 410 fm, with C. hancocki. 
2411 (2) in 400 fm, with Pro chaetoderma 
calif ornicum and C. hancocki. 
2412 (1) in 324 fm, with Limifossor fratula 
and C. hancocki. 
2441 (3) in 340 fm. 
2625 (2 ) in 230 fm, with Limifossor fratula 
and C. nanulum. 
2642 (4) in 422 fm. 
2644 (2 ) in 310 fm, with Limifossor fratula 
and C. rectum (see Fig. 12, right ) . 
2723 (1) in 325 fm, with Limifossor fratula 
and C. hancocki. 
2738 (2) in 342 fm, with Limifossor fratula 
and C. sp. 
2795 ( 1 ) in 290 fm, with C. sp. 
2798 (3) in 386 fm, with Prochaetoderma 
californicum and C. rectum. 
2802 (2) in 420 fm. 
2837 (2) in 454 fm, with Prochaetoderma 
californicum and C. sp. 
2839 (4) in 446 fm, with Prochaetoderma 
californicum and C. hancocki. 
2846 (2) in 612 fm. 
3019 (4) in 425 fm, with C. sp. 
DIAGNOSIS: Length of body 5-18 mm, width 
of body in front 0.8-2 mm, posteriorly 0 .4-0.6 
mm. The anterior half of the body, containing 
the short liver, is swollen; the posterior half 
is slender and tail-like, terminating in a button- 
like posterior end (Fig. 12). The head region is 
whitish and the rest of the body is yellowish- 
brown with dark incrustations on the hind end. 
The buccal plate is round, and the terminal 
opening of the cloacal chamber is surrounded 
by longer and shorter thorns. The spicules 
(Fig. 11) of the anterior end are small and 
squamiform; those of the rest of the body are 
lancet-like or leaflike and have a keel. The 
four groups of longitudinal muscles are lim- 
ited to the posterior half of the body; one pair 
of dorsal and one of lateral retractors occur 
anteriorly. There are five pairs of gill retractors. 
The nervous system consists of four pairs of 
precerebral ganglia. One pair of small ganglia 
connects with the buccal ganglia near the junc- 
