^■Ax. — MATi. 1S5T.] i'oyagc from England to Madras. 163 
turing any more Mollusca, although many interesting forms of 
Crustacea rewarded our efforts, a description of which is hardly 
within the scope of these pages, which however, I trust, have suf- 
ficiently shown, how the monotony incidental to a sea voyage may 
be relieved by giving attention to Zoology, facilities for which pre- 
sent themselves much oftener than might be imagined by those 
who have not practically pursued such investigations. 
References to plates IX., X., XI. a72d XII, illustratmg Mr. 
Tr rill's* /JO'joer. 
[We had hoped to receive a synoptical table of the species collected by Mr. 
Traill, but as he finds hiaiscff unable from the want of books of reference to 
assign the trival names of tho^ several specimens or to pronounce witli certainty 
which of them may be considered new, the following list has been added to facili- 
tate references to the Plates.] 
PLATE IX. 
Genus Akgonauta. 
Dorsal arms (of the female) webbed at the extremity, secreting 
a symmetrical involuted shell. Mantle supported in front by a 
single ridge on the siphon. 
Fig. 1. Animal of Argonaida sp. ? detached from the shell. Color 
light brown or horn color with crimson spots. 
Fig. 2. The Shell. 
a. Front view. 
h. Lateral view. 
Ail of the natural size. 
Genus Lanthina. 
Shell thin, trochiform ; nucleus minute, sinistral ; aperture 
foursided : column tortuous ; Up thin, notched at the outer angle ; 
color violet at the base becoming white on the spire. 
Fig. 3. lanthina exigua (magnified). 
The small figure shows the natural size. 
Fig. 4. 1. frayilis. 
Fig. 5. /. glohosa. 
Genus Atlanta. 
Shell minute, glassy, compressed and prominently keeled ; 
nucleus dextrally spiral ; o/jer/wr^? narrow, deeply notched at the keel ; 
operculum ovate, pointed. 
Fig. 6. Atlanta (magnified). 
The small fig. shows the natural size. 
