AE ees aN, 
PrarE 1 
Genus APLYSIA, Linneus. 
Testa marina, quam corpus suum multd minor, subtus 
pallium celata, cornea, intts tenuissime calcarea, 
via spiralis, aperta, expansa, ad apicem sub- 
callosu, incurva. 
Shell marine, much smaller than its body, con- 
cealed under the mantle, horny, thinly cal- 
careous within, slightly callous, incurved at the 
apex. 
Aplysie*are known all over the world. The seas of 
Europe, Asia, Africa, America, and Australia contri- 
bute species which have been observed and described 
by various authors; but the shells, or shelly mem- 
branes, being concealed under the mantle of the 
animal, very difficult to extract, and still more difficult 
to preserve when extracted, have not been well distin- 
guished or identified. Many species of Aplysia have been 
described without any notice of their shells, and in 
some cases only fragmentary membranes have been 
produced. In the present monograph little can be 
done beyond representing the forms of those shells 
which have been identified as belonging to known 
species, and adding a few undetermined species whose 
animals are unknown. 

Species 1. (Fig. a, b, Mus. Cuming in Brit.) 
APLYSIA GIGANTEA. Api. testd magna, expansd, con- 
vexd, oblique subquadratd, subviridi fusca, con- 
centrice undaté et minute strigatd, ints sub- 
testaced, pallidissimé rosed ; apice elevato, via in- 
curvo, margine superiori lato, leviter arcuato, ex- 
cavato; margine inferiori obliquo, haud excavato, 
antice oblique producto. 
Tue aicantic Aptysta. Shell large, expanded, convex, 
obliquely subquadrate, greenish-brown, concen- 
trically undated and minutely striped, within a 
little testaceous, very pale apex ele- 
vated, very little upper margin 
wide, lightly arched, excavated; inferior margin 
rose; 
incurved, 

oblique, not excavated, anteriorly obliquely pro- 
duced. 
SowWERBY. 
Hab. Swan River. 
The species has long had its place in the drawers of 
the late Mr. Cuming, but without a name. 

Species 2. (Fig. a, b, Mus Sowerby.) 
Aptysia Kerauprent. Apl. testa solidiusculd, dola- 
belliformi, alta, postice prope marginem arcuatim 
tumidd, antice planiusculd, intus alba, testaced, 
extts flavidd, corned, versiis apicem concentrice 
rugata ;  apice elevato, subcalloso; margine 
supertort profundé excavato ; ad terminum acu- 
minato, margine inferiori subexcavata. 
Keraupren’s Aptysta. Shell rather solid, shaped like 
a Dolabella elevated, posteriorly near the margin 
tumid in an arch, anteriorly rather flat, within 
white, testaceous, without yellowish, horny, to- 
wards the apex concentrically wrinkled; apex 
elevated, slightly callous, upper margin deeply 
excavated, acuminated at the end, lower margin a 
little excavated. 
Rane. Hist. Nat. Aplys., pl. 15. 
Hab, Port Jackson. 

Species 3. (Mus. Brit.) 
APLYSIA CAMELUS. Appl. testd tenwissimd, membranaced, 
subquadratd, pallidissime corned, leviter concen- 
trice rugatad ; margine superiort pauld excavato ; 
apice haud prominenti. 
THe CameL APLYSIA. 
ceous, subquadrate, very pale, horny, lightly con- 
centrically wrinkled; upper margin a little ex- 
cavated; apex not prominent. 
Cuvier. An. du Mus, v. 2, p. 295, pl. 1, fig. 1. 
Hab, ——(?) 
The authority for identifying this filmy membrane 
with the Aplysia camelus of Cuvier is that of a label in 
the British Museum. 
Shell very thin, membrana- 
August, 1869. 
