Dr. E. von Martens on the Species 0/ Argonauta. 105 



Type of Argonauta Mans : — 



a. Forma mutica : Lister, 553. 5? 



b. Forma obtusangula : Gualtieri, pi. 12. fig. c; Argenville, 5 b. A. 



Mans, Solavider, and A. Owenii, Adams and Reeve, Zool. Voy. 

 Samarang, Reeve, figs. 4 & 5, pi. 3, South Atlantic. Obtained 

 by myself at Ceram, Moluccas. 



c. Forma aurita : Lister, 554. 6 ; Rumph, pi. 1 8. fig. b, from Amboyna; 



D'Orb. Ceph. pi. 5. A. gondola (Dillwyn), Adams and Reeve, 

 Zool. Voy. Samarang, pi. 2, from the South Atlantic. A gon- 

 dola, Reeve, figs. 3* & 3b ; 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. Mans I inchne rather 

 to think the same, although very respectable authorities range 

 themselves on the opposite side ; in this the first foi*m 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 

 Z» & c of Mans 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 mu^ch more doubtful — first because 

 the want of the ears in A. Gruneri is combined with a more 

 elongated shape of the whole shell, and secondly because it 

 seems to me that the eared foru), A. haustrum, is proper to the 

 Indian seas, the obtuse-anguluted, 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. Mmstrum are prolonged in the same plane 

 with the sides of the shell, whereas they are bent outwards in 

 the eared forms of A. tuberculata and A. Mans. 



Finally, there is in the Berlin Museum a specimen, belonging 

 to the type of A. Argo, in which the aiigles 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 regai'ded rather as a fourth variation of A. Argo, espe- 



