26 GASTEROPODA. STEGOBRANCHIA. 
1. IDULIA MACULATA. 
I. flavicans carneo-maculata, branchiarum pedunculis ad apices 
sexdentatis. 
Doris maculata, Mont. Trans. Linn. Soc. vii. t. 7. fig. 8. 
Long. 4 poll. 
Habitat in Danmonie mari rarissima. 
Yellowish spotted with flesh-red, points of the branchial pe- 
duncles with six teeth. Length half an inch. 
Inhabits the coast of Devonshire, but is extremely rare. 
ORDER II. STEGOBRANCHIA. 
Tectibranches, Cuvier. 
Branchie dextree, dorsales aut laterales, sub pallii reflectione 
tectee. esta interna, externa, aut nulla. Sexus hermaphro- 
ditus. Anus dexter. 
Synopsis Familiarum, 
Fam. 1. PLEUROBRANCHID&. Branchie inter pallii et pedis 
junctionem affixe. Pallium undique dilatatum. Tentacula 
duo, involuta, labialia. Pes marginibus dilatatis. Testa sub- 
calcarea aut nulla. 
Fam. 2. Aptystap&. Branchie dextro-dorsales, operculo 
testigero (ad sinistram quasi cardine instructo) tecte. Pal- 
lium utrinque supra operculum in membranam dilatatum, 
quod ad occiput aut ad capitis dextram est productum, sypho- 
nem respiratorium efformans. Tentacula 4 mvoluta; 2 labi- 
alia; 2 antico-dorsalia. Os apertura verticali. Pes corporis 
longitudinem zequans aut aliquantulum superans, non dilatatus. 
Testa cornea, interna. 
Fam. 3. Marsenrapa. Branchie dextre testa tecte. 
Pallium testam omnino tegens, undique dilatatum ad apicem 
emarginatum. Tentacula 2 labialia, compressa, externé ad 
basin dilatata, oculigera. Os tubulosum, rotundum, Pes 
