24 
This species was found gregarious on a rocky bottom. They gene- 
rally carry the mantle lobes expanded, spreading open and exposing 
the shell and branchize. When confined in a glass jar, they used the 
posterior portion of the foot as a sucker, suspending themselves from 
the glass, although there was no division of the foot, as in the pre- 
ceding species. 
15. SypHONOTA ELONGATA. 
Form oblong, smooth. Back elevated, so much so as to give it a 
slightly compressed appearance. Mantle-lobes strongly dilated and 
undulated, and free nearly the whole length of the back. Dorsal 
tentacles rather slender and ear-shaped ; anterior pair large and di- 
lated. Foot narrow and terminating in a point posteriorly, which 
projects beyond the back. Colour of a darker or lighter brown, which 
colour is most intense on the top of the head and neck. The whole 
dorsal region is clouded and minutely speckled with white. The 
shell is distinctly defined in the living animal, being covered with a 
thin translucent membrane. 
16. ACLESIA AREOLA. 
Elongate, smooth, rounded above, rather compressed on the sides, 
and everywhere covered with small branchial filaments. Mantle- 
lobes elevated, short, rounded, and a groove extending from where 
they unite anteriorly on the back along the right side of the head 
to the mouth. Dorsal tentacles elongate and grooved laterally. 
Oral tentacles similar, but slightly dilated. Eyes a little in advance 
and slightly lateral to the base of the dorsal tentacles. Branchiz 
large, exposed or covered by the lobes of the mantle. Siphonal 
tube posterior and tubular. Foot narrow, elongated, and projecting 
far beyond the lobes of the mantle in a point. Colour cinereous or 
greenish-ash, densely and minutely veined longitudinally, and mi- 
nutely speckled and clouded with white. Remote ocellations with 
blue centres and brown rings on a fawn ground, and scatterivg simple 
brown spots. 
Length 2 inches. 
Found living gregarious among sea-weed. 
17. PLEUROBRANCHUS PELLUCIDUS. 
Mantle oval, smooth, convex above, not covering the foot behind, 
and the margins slightly undulated. Tentacles short, stout, smooth, 
truncated and grooved. Oral veil large, broad, emarginated in the 
front, which part is much prolonged laterally, so as to give it a trian- 
gular form. Eyes sessile, immersed at the posterior inner bases of 
the tentacles. Foot large. Branchize on the right side, tripinnate, 
elongate and exposed. Colour whitish translucent, and the whole 
upper surface of the mantle, with the exception of that portion 
covering the shell, minutely reticulated. Shell rather large, oblongo- 
ovate, whitish horn-colour, thin, fragile, pellucid, and rather more ob- 
tusely rounded before than behind. Surface above convex, and 
