Dr. E. von Martens on the Species of Argonauta. 105 
Type of Argonauta hians :— 
a. Forma mutica: Lister, 553. 5? 
6, Forma obtusangula: Gualtieri, pl. 12. fig. c; Argenville,5p. A. 
hians, Solander, and A. Owenii, Adams and Reeve, Zool. Voy. 
Samarang, Reeve, figs. 4 & 5, pl. 3, South Atlantic. Obtained 
by myself at Ceram, Moluccas. 
ec. Forma aurita: Lister, 554.6; Rumph, pl. 18. fig. B, from Amboyna; 
D’Orb. Céph. pl. 5. A. gondola (Dillwyn), Adams and Reeve, 
Zool. Voy. Samarang, pl. 2, from the South Atlantic. A gon- 
dola, Reeve, figs. 3* & 3,; Sow. fig. 4, from the Philippines. 
Obtained by myself at Batjan, Moluccas, from the natives. 
Concerning tuberculata, I have no doubt that the three forms 
are merely variations of the same species, as some specimens 
remain intermediate between them. For A. hians I incline rather 
to think the same, although very respectable authorities range 
themselves on the opposite side; in this the first form seems to 
be very rare, as it is the only one out of the nine which is 
wanting in the Berlin Zoological Museum. The presence or 
absence of the ears, however, is not a character of age, as both 
are to be seen in very young and in full-grown specimens, nor 
does it seem to be a difference of geographical value, the forms 
6 & c of hians having been found both in the South Atlantic 
and in the Indian Ocean. For A. tuberculata, 1 cannot find 
anywhere the geographical habitat of the eared variety separately 
stated, so as to compare it with that of the earless form. 
Concerning A. Argo I feel much more doubtful—first because 
the want of the ears in 4. Gruneriis combined with a more 
elongated shape of the whole shell, and secondly because it 
seems to me that the eared form, A. haustrum, is proper to the 
Indian seas, the obtuse-angulated, on the contrary, to the Medi- 
terranean ; but I am acquainted with the exact habitat of too 
few specimens of either form to advance anything positively in 
_ this respect. However, it seems to me not quite absurd to admit 
that some species may be rather constant and others very vari- 
able in the shape of the upper margin. It may be remarked 
that the ears of A. haustrum are prolonged in the same plane 
with the sides of the shell, whereas they are bent outwards in 
the eared forms of A. tubercu/ata and A. hians. 
- Finally, there is in the Berlin Museum a specimen, belonging 
to the type of A. Argo, in which the angles are present but 
little developed, and not free but. firmly joined to the spire, in 
consequence of which, at first sight, one might suppose them to 
be entirely absent; the shell is more compressed and more 
elongated than that of A. Argo generally; its coloration is 
typical of that species. This seems to be a very well-charac- 
terized species; but I cannot help suggesting whether it may 
not be regarded rather as a fourth variation of A. Argo, espe- 
