232, MR. L. N. G. RAMSAY ON 
the maxillary ring is intermediate between those described by 
Grube and Izuka. Moreover, the smallest of these three speci- 
mens (which are all in the heteronereid state) has these papille 
distinctly less swollen and conspicuous than the two larger ones. 
It is to be noted that Izuka’s specimens were from the same 
locality as these (the Sumida River). 
Further, Izuka himseif (1903, p. 9) states that the papille on 
the neural surface of the maxillary ring seem to increase in 
number with the age of the individual, and that in larger 
specimens their number varies from 17 to 27. 
Further still, Izuka describes the proboscis of the worm in the 
nereid-form only, while Grube’s specimens as they are figured 
were in the heteronereid condition. It is conceivable that as the 
worms assume the heteronereid form, the changes in the posterior 
region of the body may be accompanied by some swelling of the 
areas between the deep furrows which exist in the basal ring 
in the immature form. Unfortunately, none of the immature 
specimens at present before me has the proboscis everted, and 
the method of examination by slitting open this organ does not 
give very satisfactory results, owing to ‘the difficulty of recognizing 
the soft papille in the compr essed condition resulting from the 
inverting of the proboscis. 
It appears, therefore, that there is no ground for even the 
specific separation of chinensis and osawai, and the latter name 
must therefore stand as a synonym of Tylorhynchus chinensis 
Grube. 
The relationship of the Genera Ceratocephale and Tylo- 
rhynchus.—These genera were described independently by 
Malmgren and Grube in the year 1867. Since that year, 
various authorities have mentioned them in their schemes of 
classification of the Nereide, but their characters, especially those 
ot Tylorhynchus, do not appear to have been properly com- 
prehended. Matters were further confused when a species of 
the latter was referred to the former genus by Izuka in 1903, 
as explained above. 
We must first consider whether the two genera should be 
regarded as distinct. On this head I think it will be agreed 
that the divergences are sufficient to warrant generie separation, 
although the two, one of which is, so far as known, confined to 
the Atlantic, the other to the Pacific Ocean, are certainly much 
more closely allied to one another than to any other genus. 
he chief points of difference appear to be as follows * :— 
In Tylorhynchus, 
(a) The parapodium lacks the neuro-ligule 
(6) The neuro-cirrus is normal. 
(c) Eyes are present. 
* T have not had an opportunity of examining specimens of Ceratocephale, 
which has, however, been figured and described by Malmgren (1867), McIntosh 
(1902), and Heinen (1911). 
