GASTEROPODA TECTIBRANCHIATA. 347 



Jlpl. depilans, L.; Bohatch., Anim. Mar. pi. i and ii; Rang, 

 pi. xvi. Blackish, with large greyish, clouded spots. 

 Several other species are found in distant seas(l). 



DoLABELLAj Lam. 



The Dolabellse only differ from the Aplysiae in the position of the 

 branchiae and their surrounding envelope; they are at the posterior 

 extremity of the body, which resembles a truncated cone. Their 

 lateral crest presses closely on their branchial apparatus, merely 

 leaving a narrow furrow; their shell is calcareous. They are found 

 in the Mediterranean and in the Indian Ocean(2). 



NOTARCHUS, CuV. 



The lateral crests united and covering the back, a longitudinal emar- 

 gination excepted, that leads to the branchiae, which have no man- 

 tle to cover them, but are otherwise like those of the Aplysiae ; the 

 rest of their organization is always the same(3). In the 



BuRSATELLA, Blainv. 



The lateral crests are united in front in such a manner as only to 

 leave an oval aperture for the transmission of water to the branchiae, 

 which are also deprived of a protecting mantle(4). 

 These two genera, however, probably form but one. 



(1) Splysia hrasiliana, Rang-, pi. viii, 1, 2, 3; — A. dadylomela. Id., IX; — A. pro- 

 tea. Id., X, 1; — A. sorex. Id., X, 4, 5, 6; — A. tigrina, Id., XI; — Jl. maculata. Id. 

 XII, 1 — 5; — A. marmorata, Blainv., Journ. de Phys., Janv., 1823, Kang-, XII, 6, 

 7; — A. Keraudrenii, Id., XIII; — A. Lessonii, Id., XIV; — A. camelus, Cuv., Ann. du 

 Mus., and Rang-, XV, 1; — A. alba, Cuv., lb., and Rang, XV, 2, 3; — A. napoUtana, 

 Id., XV, bis; — i. virescens, Risso, Hist. Nat. Mer., pi. 1, 7. It is well, however, 

 to observe, that most of the Aplysije having been drawn from specimens preserved 

 in spirits, the truth of tlie specific characters of some of them may be doubted. 



(2) Dolahella Rumpidi, Cuv., Ann. du Mus., V, xxis, 1; and Rumph. Thes. 

 Amb., pi. X, 6, from the MoUuccas, or Aplysia Rumphii, Rang, pi. i; — Apl. ecau- 

 dala. Rang, pi. ii; — A. truncata. Id.; — A. teremidi, Id. Ill, 1; — i. gigas, Id., Ill, 

 4;— A. Hasseltii, Id., XXIV, 1. 



(3) Notarchus gelatinosus, Cuv., to which M. Rang associates the Bursafella Sa- 

 vigniana, Descr. de I'Eg., Zool., Gaster., pi. ii, f. 1, 2, and Rang, Apl, pi. xx, and 

 his Apl. Pleii, pi. xxi, and some small species. 



(4) Bursatella Leachil, Blainv., Malac, pi. xliii, f. 6. 



N.B. Authors have also approximated to the Aplysiae the Apl. viridis, Jlontag., 

 Lin. Trans., VII, pi. vii, which forms the genus AcTeon of Oken, and which is at 

 least closely allied to the Elysie fimide, Risso, Hist. Nat. Mer., IV, pi. i, f. 3, 4; 

 as I am not acquainted with the branchiae of either, I cannot class them. 



