POLYCLAD FLATWORMS — HYMAN 571 



Differential diagnosis: The blue border distinguishes this species 

 from other black species with a colored border. This pattern, black 

 with a narrow border of a bright contrasting color, is common among 

 species of Psevdoceros, but usually the border is red, orange, or yellow, 

 and I know of no previously described species with a blue border. 



Holotype: USNM 28653, in alcohol. 



Pseudoceros ferrugineus, new species 



Figure 96, c 



Material: The single specimen was taken by the Stanford team 

 at Sta. 236a, in Iwayama Bay, Palau Islands, Oct. 20, 1955, crawling 

 in about a meter of water on the rocky shelf of the east end of Koror 

 Island, in Oyster Pass. 



General characters: The worm is of elongated oval shape (fig. 

 9b), measuring 18 mm. in length by 11 mm. in width, preserved. 

 The tentacular foldings appear slightly developed, both in the pre- 

 served worm (fig. 9c), and on the color photograph of the live worm. 

 The brilHant coloring in life is preserved on the photograph taken by 

 F. M. Bayer, but, alas, the preserved worm is a dull grayish brown. 

 In life the general color is a bright rusty red blending into a narrow 

 margin of brilliant orange. The dorsal surface is liberally flecked 

 with white on the rusty background and here and there these flecks 

 fuse to form nebulous patches of clear white or tinged with pink in 

 places. The white flecks diminish towards the margin where the 

 rusty red background is much more in evidence. The bright orange 

 marginal line is free from spots. There is some indication of a narrow 

 middorsal line of pale rust that fades away posteriorly. 



In the cleared worm (fig. 96) there could be seen the shghtly bilobed 

 cluster of cerebral eyes (fig. 9c), the ruffled pharynx having the but- 

 terfly shape that I have noticed in some species of Pseudoceros, the 

 pair of male pores in the concavity of the last lobulations of the 

 pharynx, the female pore close behind the male pores, and the sucker 

 slightly behind the middle, about 10 mm, from the anterior end. 



Differential diagnosis: The color pattern is distinctive, 



Holotype: USNM 28654, in alcohol, 



Pseudoceros ater, new species 



FiGUBE 9d 



Material: The single specimen was taken by the Stanford team 

 on Raeldil reef, Palau Islands, Sta, 254, Oct. 27, 1955. It was col- 

 lected at night with a light on the outer reef flat among branching 

 corals. 



General characters: This is a small worm, measuring 9 by 7 mm. 

 preserved, although evidently somewhat contracted, hence longer in 



