JAPANESE NUDIBEANCHS. ]9 



are entirely closed but appear to have been stellate and perhaps 

 somewhat raised. The branchial pocket is raised, distinctly six- 

 stellate, and closed, The posterior lobe is considerably larger 

 than the others and covers some part of all of them. The bran- 

 chiae are pinkish, but bear very numerous fine black lines, which 

 produce a general effect of grey. It is difficult to see the pa^ts 

 near the mouth, as the naturally hard integuments are much 

 contracted but the anterior margin of the foot seems to be 

 grooved and notched and the oral tentacles are large and furrowed. 



There is no labial armature. The raclula consists of 50 rows, 

 rather crowded and containing as many as 150 teeth. The teeth 

 have rather long bases and slender erect shafts, the tips of 

 which are often blunt. The two outermost are rather degraded 

 in shape and not hamate. They are not regularly serrulate but 

 they often bear (especially the last one) a few irregular denticles. 



The intestines, as so often happens in specimens of this 

 genus, 15 were dry and hardened but by a careful examination of the 

 genitalia it seemed possible to identify both the vagina and vas 

 deferens. They are thick tough tubes conspicuous on account of 

 the thick yellow cuticle with which they are lined. In this 

 specimen both bear strong zig-zag folds and lumps, but no hooks 

 or spines whatever were found. 



It is with some hesitation that I refer this specimen to PL 

 striata, characterized by having no red blotches on the back but 

 numerous dark lines and by having no disks or spines on the 

 male genitalia. The buccal parts are practically as in PL cruenta. 

 My examination of the much damaged specimen labelled D. 

 striata by Alder and Hancock which is preserved in the New- 

 castle Museum (P. Z. S. 1906 p. 647) supports this diagnosis and 

 I have found the same absence of spines and disks in a speci- 

 men kindly lent me by the British Museum. But it must be 

 remembered that in dealing with old, dried, specimens it is dif- 

 ficult to demonstrate conclusively the absence of a spiny arma- 

 ture in the genitalia. If this is consistently absent, the present 

 form will be a valid species. If it proves to be present, PL striata 



1) Probably the hard thick integuments do not allow the preserving fluid to pass. 



