INNERVATION OF CERATA OF SOME NUDIBRANCHIATA. 6541 
On the Innervation of the Cerata of some 
Nudibranchiata.' 
By 
Ww. A. Herdman, D.Sc., F.L.S., 
Professor of Natural History; 
AND 
J. A. Clubb, 
Assistant in the Zoological Laboratory, University College, Liverpool. 
With Plates XXXII, XXXITI, and XXXIV. 
A FEW years ago (1889) one of us read a paper at the 
Newcastle-on-Tyne meeting of the British Association “‘On 
the Structure and Functions of the Cerata in Nudibranchiata,” 
in which these dorso-lateral processes were regarded as being 
probably epipodial outgrowths. In other papers” published 
since, we have compared the conditions of these structures in 
various genera of Nudibranchs, and have tried to show that 
they are all modifications of simple lateral epipodial ridges. 
Garstang also, in papers® published about the same time, came 
independently to the same conclusions from the examination of 
a somewhat different series of forms. 
Pelseneer* and others, however, have lately contended that 
1 Read (in abstract) before Sect. D of British Association, Cardiff, August 
24th, 1891. 
2 Herdman, ‘Quart. Journ. Micr. Sci.,’ vol. xxxi, p. 41; and Herdman 
and Clubb, ‘Trans. Biol. Soc. Liverpool,’ vol. iv, p. 131. 
3 ¢ Journ. Mar. Biol. Assoc.,’ N.8., vol. i, No. 2, p.173; and No. 4, 
p. 399. 
4 «Bulletin Scientif.,’ 1888, p. 182; and 1890, p. 138, 
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