OPISTHOBRANCHIATA FROM THE ABEOLHOS ISLANDS. 577 
EXPLANATION OF THE PLATES. 
Plate 27. 
The photograplis on this plate were all taken by Mr. Herring, of the British Museum. 
Eig. 1. Tethys yiyantea (Sowerby). Dorsal aspect, X about 2/.3. The large expanded 
lobes at the anterior end of the foot and the anal funnel are clearl}' shown. 
Fig. 2. Tethys denisoni (Smith). Dorsal aspect, X 1. The anal funnel in this specimen 
is folded in. 
Fig. 3. Dolahrif era pelsartensix, s'f.-nov. Dorsal aspect, X 1. 
Fig. 4. P/acobra-iichus expansa, sp. nov. Dorsal aspect, X 1. The anterior e.xtension of 
the mantle lobe in front of the flattened head shows clearly on the right side, 
but is torn and folded on the left. The anterior end of the head with the 
tentacles is withdrawn and does not show. The tiny pericardial swelling 
appears ,just behind the head. Owing to the shadow produced by lighting, a 
false impression of a solid body is given. In reality this region is mainly com- 
posed of the mantle lobes, and the actual body is not quite as wide as the head; 
it cannot be distinguished from the lobes. 
Fig. 5. Sphcerostuma dakeni, s-g.TaoY. Ventral aspect, xL The mouth shows as a longi- 
tudinal cleft at the anterior end, and part of the oral vefl with one projection 
appears on the left-hand side. The margins of the foot in this specimen are 
almost approximated. Some of the large branchiaj show clearly on each side. 
Fig. 6. AUoiodorls hedleyi, sp. nov. Dorsal aspect, x 1. The granulate appearance of 
the back and the nature of the branchial and rhinophoral apertures are clearly 
visible. 
7. Ventral aspect of the specimen illustrated in fig. 6, X 1. The tiny head 
is not visible. 
Fig. 8. Glossodoris westraliensis, sp. nov. Dorsal aspect, x 1. Tiie dark band near the 
margin of the notfeum shows faintly. 
9. Lateral aspect, X L The broad dark band on the side of the body and 
the narrow one on the upper edge of the flange of the foot are visible. The 
front end of the foot is clearly bilabiate. 
Fif. 10. Apheloduris affinis Eliot. Dorsal aspect, X 1. In places the darker line around 
the notseum is seen, and the dark-coloured branchiae show in the circular spot 
towards the posterior end. 
Plate 28. 
The photographs on this plate were all taken by Mr. Herring, of the British Museum. 
Fi". 11. Hexabranchus imperialis Kent, Dorsal aspect, X 2/.3. The branchife and the 
clavus of the right rhinophore are clearly visible, and the relatively enormous 
size of the mantle folds can easily be judged. 
Fig. 12. Asteronotus fuscus, sp. nov. Dorsal aspect, x 1. This shows the ridges in the 
central region of the dorsum. 
13. Ventral aspect of the specimen illustrated in fig. ]2, xl. The relative 
sizes of the foot and mantle show clearly. The indentation at the po.s*erior end 
is where a portion of the mantle has been broken away. 
Fio-. 14. Ceratusoma brevicaudatum Abraham. Dorsal aspect, X 1. The tail is bent to the 
right, otherwise this gives a good idea of the shape of the animal and also the 
position of the rhinophoral and branchial apertures and the tongue-like prolon- 
gation of the dorsum. 
LINN. JOURN. ZOOLOGY, VOL. XXXV. 41 
