JAPANESE NUDEBRANCHS. 5 



all round the body. The back is tuberculate and, as is usual 

 when many specimens of one nudibranch are examined, there is 

 great diversity in detail. As a rule the tubercles show remark- 

 able differences of size in the same specimen. The commonest 

 arrangement is that the whole back is covered with small tuber- 

 cles (1 mm. — 2 mm. broad), among which are scattered 20-30 

 much larger tubercles 4 mm. or even 5 mm. broad. These assume 

 various shapes, being sometimes flat and sometimes, especially in 

 the larger specimens, slightly constricted at the base and clavate. 

 In the majority of specimens each rhinophore opening is protected 

 by two or three large tubercles, but in some instances these are 

 not noticeable. Similarly the branchial pocket is studded with 

 tubercles which occasionally (though not very often) are sufficient- 

 ly developed to merit the name of protective appendages. When 

 the branchiae are spread out they appear to be in all cases six, 

 but very often two have a common base so that strictly speaking 

 there are only five. As in D. tuberculata the tentacles are lumps 

 at the side of the mouth. In many specimens they are clearly 

 grooved on the under side and probably are so in all in life. 



There is no trace of jaws or other armature on the labial 

 cuticle. The teeth are simply hamate and the maximum formula 

 of the radula is about 60x70. 0. 70. 



The anatomy of this species has been described by Bergh 

 (I.e.) who made it the type of a new genus Homoiodoris on ac- 

 count of some peculiarities in the genitalia. But as I have ex- 

 plained elsewhere 15 I think it should be regarded as belonging to 

 Doris and as forming merely a subgenus. 



Doris (Cteuoiloris) aurantiaca sp. now 



? = Doris pecten Collingwood. 

 For genus see Eliot: Nudibranchs of New Zealand, in Proc. Mal. Soc. 1907, p. 338. 



(Plate I., fig. 1). 



Two specimens from Misaki, accompanied by a coloured 

 figure representing a yellowish brown Dorid with dots of a 



1) Supplement to Alder and Hancock's Britisa Nuäibrancn'iate Mollusca. Ray Society 1910, 

 p. 95. 



