THE GASTROPODA 177 
TRIBE 2. DORIDOMORPHA. 
Nudibranchia with external symmetry, in consequence of the median 
position of the anus, which is posterior and generally dorsal, and sur- 
rounded by ramified pallial appendages constituting a secondary branchia 
(Fig. 162, 9). The liver is not ramified in the integuments. The genital 
duct triaulic. Spicules present in the mantle. 
Famity 1. Ponyceratipar, Abraham. A more or less prominent 
frontal veil; branchiae non-retractile. Genera—Huplocamus, Philippi 
(Fig. 162); ramified dorsal appendages on the border of the mantle. 
Fic. 163. 
Ancula cristata, dorsal view. a, 
anus; br, pallial gill encircling the 
Fic. 162. anus (external to these respiratory 
appendages are seen ten other club- 
Ewplocamus croceus, dorsal aspect. like pallial appendages); t, posterior 
a, anus ; f, foot; fr.a, frontal append- (branched) cephalic tentacle or rhino- 
ages ; g, gill; pa.a, pallial appendages ; phore. (From Lankester, after Alder 
rh, rhinophore. (After Vayssiére.) and Hancock.) 
Polycera, Cuvier ; the mantle border bears on each side a single posterior 
pointed appendage; British. Thecacera, Johnston; the mantle border 
with club-shaped appendages ; the branchia formed of three lobes directed 
forwards ; British. Aegirus, Loven ; body tuberculate ; rhinophores not 
lamellar ; a dorsal mandible; British. Plocamopherus, Leuckart. Palio, 
Gray. Crimora, Alder and Hancock. Triopa, Johnston, British. T'rio- 
pella, Sars, Faminy 2. GonroporipipAr, Adams. Mantle border pro- 
jecting ; frontal veil reduced and often covered by the anterior border of 
the mantle. Genera—Goniodoris, Forbes ; frontal veil not continuous 
with the mantle ; mantle quadrangular and incised posteriorly ; British. 
Acanthodoris, Gray ; mantle oval, papillate ; rhinophores retractile ; British. 
Idalia, Leuckart; mantle reduced and fringed with long appendages ; 
12 
