I've hosted all the photos described below here: http://www.picturetrail.com/gallery/view?p=999&gid=4081363&uid=2101892&members=1
(Note: The pictures are of a high resolution so they may take some time to load.)
The first photo is of Argonauta hians "No. 1" which seems to be a very common type. Shells of this Argonaut are usually cream or light sepia in colour and are quite compact. The shell's surface is very smooth with ribs which are barely visible. The tubercles (knobs on top of the shell) are very small and rounded. I have found that shells of this type of A. hians usually don't get very large. Most specimens which I have seen are below 6 cm in size and I have never seen any over 9 cm. Most representatives of this form seem to come from the Philippines.
The second and third photos is of Argonauta hians "No. 2" which seems to be uncommon. This type seems to grow much larger; i have seen numerous specimens past 10 cm (I myself have a shell of 122 mm, a WRS). The shells of this variant of hians usually have a much darker colour (dark brown to even black) and display much more prominent tubercles and ribbing. They also display large "spikes" protruding from both sides of the shell (visible in the second photo of the representative of this variant). A. hians "No.2" seems to be most abundant in the waters surrounding Taiwan and Japan.
Photos 4 through to 6 display different specimens of Argonauta boettgeri, a species often confused with A. hians. These shells seem to be the smallest of all the paper nautiluses (the WRS is listed at a mere 61.9 mm). A. boettgeri originates from Southern Africa (especially Mozambique, where most specimens are from). These are rare finds and vary wildly in degree of pigmentation (as can be seen in the three pics), but most seem to be of a dark colour (dark brown/black). The specimen from S. Africa in photo No. 6 seems to be an "albino", displaying almost a complete lack of pigmentation (sorry for the bad photo - it's the best one I could take o_0). Another characteristic of this species is that the shells are usually finely granulated and display promiment tubercles and well developed ribs (which are usually "wavy"), which alternate in length (one long, one short, etc.).
Photo number 7 is of the very rare Argonauta nouryi. The shell pictured is 87.3 mm in length (my other specimen is 93.9 mm - WRS?), which is at the higher end of their size range. This is one of the rarest Argonauta species and can only be found in the waters around Mexico and Baja California. If my memory serves me well then there have only been two known strandings of this species (both my shells came from the 1992 stranding). The shells of this species cannot be confused with any other being probably the most elongate of any paper nautilus. The shells are of a white or cream colour (with the oldest tubercles having a brownish pigmentation) and possess numerous small knobs on the keel. The surface of the shell is very smuth and has a large number of underdeveloped ribs.
The final photo is of a curious specimen of a shell which seems to share traits of several different species. For the most part it looks like A. boettgeri: it is of a dark colouration and displays very
prominent tubercles and ribbing (having the characteristic "wavy" shape). It is also finely covered in small "granules", another characteristic feature of A. boettgeri shells, but it is well outside its normal size range at 75 mm (which would make it the World Record Size by almost 1.5 cm) and displays those prominent spikes which in the description for A. hians "No. 2". Also, this specimen came from Taiwan waters, on the other side of the world when compared to the known distribution of A. boettgeri. Could it be A. cornuta?? I am not sure as the few photos which I have seen that supposedly show this species are very conflicting and also do not seem to show a distinct species. Due to the lack of knowledge on this subject I cannot positively identify it for the moment.
Please let me know if you would like to see any more Argonauta (or Nautilus) shells as my collection consists of over 80 specimens, so this is only a small fraction of it.
Also, I would be interested to know if anyone knows how large Nautilus shells actually get or has any information on the validity of the species Nautilus repertus. In the 2001 edition (newest) of "The Registry of World Record Size Shells" the largest Nautilus pompilius specimen is listed at 253 mm. A shell which I received labelled Nautilus repertus is considerably larger than this at 268 mm, so I am curious as to how large these creatures actually get.
Look forward to reading your replies,