GASTEROPODA IN EEROBR ANCHIAT A. 
43 
Flabellina, Cuv. 
The tentacula of the Eolidiae, with radiating rectiform branchiae, 
supported by five or six pedicles on each side ; they are closely allied 
to the Glauci, and in fact to all the Nudibranchiata, whose branchiae 
are situated on the sides of the back*. 
Tergipes, Cuv. 
The form of the Eolidiae, but only two tentacula, with a range of 
cylindrical branchiae on both sides of the back, each of which is ter- 
minated by a little sucker or cup, and which are used by the animal 
as feet, to walk on its back. The species known are very smallf. 
Busiris, Risso. 
The body oblong, and back convex ; two filiform tentacula, and 
behind them, on the nape, two plumiform branchiae I". 
Placobranchus, Van Hasselt. 
Two tentacula and as many labial lobes; the whole back, widened 
by its margin, is covered with numerous radiating striae, which are 
the branchiae. In its ordinary condition the widened borders of the 
mantle are turned up, and cross each other to form an envelope for 
the branchiae, which are thus enclosed, as in a cylindrical case. 
They are small Mollusca, from the Indian Ocean ||. 
ORDER III. 
INFEROBRANCHIATA. 
The Inferobranchiata have nearly the same form and organization 
as are observed in Doris and. Tritonia, but their branchiae, instead of 
being placed on the back, resemble two long series of laminae, situated 
on the two sides of the body, under the projecting margin of the 
mantle. 
* Doris affinis, Gm. Cavol., Polyp. Mai-., VII, 4. 
■t Limax tergipes, Forsk., XXVI, E, or Doris lacinuluta, Gm. ; — Doris macu- 
lata, Lin. Trans., VII, vii. 34 ; — Doris piennata, Bomm^, Act. Fless., I, iii, 3. 
J Busiris griscus, Risso, Hist. Nat. Mar., IV, pi. i, f. 6. 
II In the species known {Placobranchus Hasselti, Cuv.), the branchial striae are 
green, and the body a brown-grey sprinkled with little ocelli. Van Hasselt., Bul- 
let. Univ., Oct., 1824, p. 240. Messrs Cluoy and Gaymard found it at the 
Friendly Islands. 
