292 SER Css HDLOM AND ic ee VOAUNISS 
mented not replaced by the action of accessory gills. It may 
even be said that the AJolids and many other cerata-bearing 
Cladohepatica have nothing but pallial respiration, for the 
cerata and the hepatic ramifications which they contain are 
not so much special respiratory organs as a special disposition 
of other organs arranged so as to facilitate pallial respiration. 
But the following genera have neither this arrangement nor 
accessory gills.? 
Tritonidoxa, Bergh.” Similar to Tritonia in all respects 
except that it has a broad, undulating dorsal margin without 
any trace of branchial tufts. Dorsal surface smooth. Size 
(32 mm.) moderate. 
Tritoniella, Eliot.* Similar to the last genus, and lke it 
resembling Tritonia in most peculiarities, but the dorsal 
margin, which is wide, bears simple unbranched prominences 
and not foliaceous tufts. The back bears ridges. Rather 
large (65 mm.). 
Doridoxa, Bergh.t Doridiform in appearance and holo- 
hepatic. Blood gland and two spermatothecas. But there 
are no branchie, the anus is lateral, jaws are present, the 
1 We have not taken into consideration Pseudovermis or the Hedy- 
lide. The former appears to be a retrograde Alolid. The systematic 
position and relationship of the Hedylide are not clear. ‘The same may be 
said of Timorella (Bergh, ‘Siboga Hxp., Opisth.,’ p. 241, 1905). 
2 “Ueber clado- und holohepatische nudibranchiate Gastropoden,” ‘ Zool. 
Jahrb. Syst.,’ 23 Band, 6 Heft, 1906; and “Marine Investigations in 8. 
Africa,” vol. v, part i—Opisthobranchiata, pp. 86—88, in ‘Trans. 8. Afr. 
Phil. Soe.,’ vol. xvii, 1907. . 
3 Eliot, ‘National Antartic Expedition (Discovery) Nudibranchiata,’ 
1907, pp. 5—11. Tritoniella seems generically distinct from Tritoni- 
doxa since it has dorsal ridges and prominences on the dorsal margin. If 
the two genera are regarded as synonymous the name Tritoniella has 
priority. The description was published on March 5th, 1907, and the chief 
characters had already been named June 9th, 1905 (Kliot, ‘Trans. R. Soc. 
Edinburgh,’ vol. xli, part 111, No. 22, p. 525). The description of Tritoni- 
doxa appeared on March 14th, 1907, the chief characters having already been 
named by Bergh in ‘ Zooi. Jahrb. Syst.,’ 23 Band, 6 Heft, 1906. 
4 In ‘Danish Ingolf Expedition,’ vols. 2, 3, 1900, ‘“‘ Nudibranchiate Gas- 
tropoda.” 
