Description of Some Japanese Poïjhciaa Tïiîrbellaria. 37 



18. Pseudoceros lacteus ( 'olltngwood) ? 

 (PI. L, fig. 6). 

 Spkyngiceps lacteus, Collingwood 1876, p. 90. 

 Psendoceros (?) lacteus, Lang 1884, p. 548. ; 



Two individuals, not improbably referable to this species, were 

 found attached to brown alga? between the tide-marks at Misaki. 



Body oval, with frilled margin, reaching 20 mm. in length 

 and 10 mm. in breadth. 



Dorsal surface rosy colour with a number of scattered blackish 

 spots of a moderate size and a lightly coloured median stripe extend- 

 ing posteriorly from behind cerebral eye-spots; with a blackish 

 marginal and a russet brown submarginal band all around. 

 Ventral surface pale, revealing the same marginal and submarginal 

 bands seen on the dorsal side. 



Marginal tentacles represented by folded flaps of the anterior 

 margin, which flaps are provided with numerous ' eye-spots on 

 both dorsal and ventral sides. Cerebral eye-spots in a median, 

 roundish, clear space behind the tentacles. • 



Sucker nearly in the centre of ventral surface. Mouth 

 anterior, situated at a distance of 3.5 mm. from the anterior body 

 end, leading into the lobed pharyngeal chamber. Main gut extends 

 backward to near the hind end of body. 



Male and female genital openings approximated, placed close 

 behind pharyngeal chamber. Internal genital organ- quite similar 

 to those of the preceding species. 



The Misaki specimens we have observed seem to tally well 

 with Collingwood' s Spkyngiceps lacteus from Singapore, so far as 

 the existing incomplete description of this goes. They are also 

 not unlike Eurylepta japonica described by Stimpson from Hok- 

 kaido, but stand distinctly at variance from it chiefly in the 

 presence of blackish spots on the dorsal surface. 



L9. JPseudocet'os lttteotnarginattis 9 n. sp. 



(PI. T., fig. 5.— Toxtfig. 40). 

 This new species is based on four individuals obtained near 

 Misaki at the low-water mark. 



