Fam. 1, Plate 10. 



DORIS DIAPHANA, Alder and Hancock. 



D. alba, pellucida : pallio tuberculis clavatis : branchiis 11, pinnatis, anum non propinque 

 cingentibus. 



Doris diaphana, Aid. and Hanc. in Ann. Nat. Hist. v. 16, p. 313. 

 Bab. Under stones near low-water mark, Meadfoot Sands, Torbay. 



Body nearly half an inch long, and about half as broad, elliptic oblong, equally rounded 

 at both ends, and not much depressed, of a pale yellowish white, very transparent, showing 

 the intestines through the skin. Cloak extending a little beyond the foot all round, but 

 rather more at the sides, covered with largish clavate tubercles, mostly of equal size, but 

 having a few smaller ones amongst them on the back ; those round the margin more thickly 

 set and a good deal smaller. The spicula are seen through the transparent skin lying across 

 the back, and sloping diagonally down the sides ; those of the tubercles are small, and 

 diverge towards the top. Tentacles nearly linear, pale yellow or yellowish white, transparent 

 below, laminated with eight plates sloping very obliquely down behind ; margins of the 

 apertures nearly smooth, without sheaths. Branchial plumes eleven, simply pinnate, and 

 partially retractile within a slight groove, set in an incomplete circle round the vent, leaving 

 a tuberculated area within. Head with a large semicircular veil. Foot yellowish white, 

 rounded in front and obtusely pointed behind, scarcely produced beyond the cloak, very 

 transparent, showing the liver through the centre in a large, very dark, blackish-brown 

 patch. 



The spicula tire unbranched, smooth and crystalline, a little bent in the centre, and 

 tapering at the ends. 



This Doris approaches nearest to D. bilamellata, but, besides the difference in colour 

 and transparency, the branchial plumes are fewer, and arranged in a more circular form. 



Two specimens were found under the same stone, in the locality above mentioned, about 

 the middle of May, 1845, at which time they were spawning. The spawn is attached to 

 stones, and forms a coil of two volutions of moderate width, sloping a little inwards at the 

 upper margin. 



Fig. 1, 2, 3. Doris diaphana in different positions. 



4. Tentacle. 



5. Branchial plume. 



6. Tubercles of the cloak. 



7. Spawn. 



8. A portion of the same more highly magnified. 



9. Spicula. 



