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Proceedings of the Royal Society 
end being narrower; not compressed, erect; anterior end wide, con- 
vex. Attached by the posterior end. Apertures both at the 
anterior end, moderately far apart, not conspicuous. Surface en- 
tirely covered by a layer of sand. Colour yellowish-brown. 
Length, 6 mm. ; breadth, 4 mm. 
Test thin but strong. 
Mantle rather strong, muscular fibres delicate but very numerous, 
forming a close network. 
Branchial sac with four folds on each side. Transverse vessels 
all equal in size. About eight internal longitudinal bars on the 
folds and the same number in the interspaces. Meshes vertically 
elongated, containing each three stigmata. 
Dorsal lamina plain. 
Tentacles filiform, about twenty large ones, with one or two 
smaller between each pair. 
Olfactory tubercle irregularly horse-shoe shaped, both horns rolled 
inwards. 
About a dozen specimens from Bahia, 7 to 20 fathoms. 
Poly car pa tinctor , Quoy and Gaimard.* 
About a dozen specimens of this species from Port Jackson, at 
depths varying from 2 to 15 fathoms. 
Poly car pa viridis , n. sp. 
External appearance . — Shape more or less pyriform, the anterior 
end being the broadest, and the posterior forming a short stalk, 
sometimes more elongated and twisted, by the lower end of which 
the animal is attached. Both apertures at the anterior end, generally 
a little to the right side ; branchial terminal, or subterminal ; 
atrial a short way down the dorsal edge, not distant from branchial ; 
both four-lobed, sessile, inconspicuous. Surface not uneven but 
generally more or less covered by animals, sand, shell fragments, 
&c., adhering to it. Colour dull green, darkest in the neighbour- 
hood of the apertures. Length, 3 cm.; breadth, 2 ‘5 cm. 
Test not thick but tough, rough externally from adhering sand, 
&c., of a beautiful dark-green colour throughout. Vessels very 
numerous, anastomosing frequently. 
* Voyage de 1’ Astrolabe, Zoologie, tom. iii. p. 608, pi. xci. figs. 1, 2. 
