Organizing a Shell Collection

by Dr. Gary Rosenberg
As a shell collection grows, by self-collecting, trade or purchase, it can become impossible to display all the shells. One solution is to house the collection in cabinets with shallow drawers. Each lot is placed in a cardboard tray or plastic box with its label. A lot consists of all the specimens of one species collected in one place at one time. Lots are kept in order by their classification, often alphabetized by genus and species within a family.

People with large collections often number their lots, and keep a hand-written catalogue recording the information associated with them, to safeguard against misplacement of specimens and labels. Catalogue numbers are assigned in consecutive order (although they need not start from one). The number should be written in india or other indelible ink on the labels and the shells. Collectors reluctant to write on their shells should record the measurements of the specimens, especially if they have more than one example of a species. Specimens too small to be written on can be put in cotton-plugged vials or plastic boxes, along with the catalogue number on a slip of paper.

Today, shell collections can be easily computerized with a home computer and a data base program. Computerization serves two functions. First, it allows information to be sorted in various ways, so that, for example, labels can be printed and lists of species from particular families or parts of the world can be generated. Second, it ensures that all the information about a specimen is recorded, by giving a more detailed list of items to be recorded than is possible in a hand-written catalogue. This enhances the value of the collection, particularly if the collector is planning eventually to donate it to a museum. (A computerized collection is also much easier to appraise.)

About two dozen fields of information are sufficient for the needs of most collectors. All the fields pertaining to a particular lot are called a record. Examples of types of information that a collector might want to include in a record are shown below. The number of characters recommended for the length of the field is shown in parentheses. Comments about the contents of some of the fields are provided below.

Catalogue number (6) 101237
Class (14) Gastropoda
Order (20) Caenogastropoda
Superfamily (20) Tonnoidea
Family (20) Ranellidae
Genus (20) Charonia
Subgenus (22) (Charonia)
Species (22) tritonis
Subspecies (22) variegata
Author (31) Lamarck
Year Named (4) 1816
Parentheses (1) y
Continent (13) North America
Ocean (16) Western Atlantic
Country or Island Group (25) United States
Subdivisions of above (80) Florida Keys, Monroe County, Florida,Gulf of Mexico
Specific locality (80) Bay at northeast end of Vaca Key by Marathon airport
Habitat (80) Living at 3 meters in Thalassia bed
Station Number (10) CR80-114
Date collected (11) 19 SEP 1980
Collector(s) (30) Richardson, C.
Number of specimens (4) 1
Size (30) 267 x 149 mm
Source (30) Novel Shell Shop
Cost (8) $20.00
Date obtained (11) 15 NOV 1983
Date catalogued (11) 07 APR 1991
Remarks (255) Collected by SCUBA. With operculum.

Catalogue number: Each lot receives a unique catalogue number, which ties together the specimens, labels and record.

Classification: The most often used ranks are listed, and others, such as subfamilies and suborders can be added as desired. The fields lengths shown are a couple of characters longer than the longest name of each rank that I know of: order Systellommatophora; superfamily Architectonicoidea; family Prochaetodermatidae; genus Nipponocrassatella; species roseoprodissoconchus (for a venerid in the genus Pitar) and extracarinacostata (for a omalogyrid snail less than 0.5 mm long in the genus Ammonicera). A more sophisticated user might want to store the higher classification in a separate file, linking the files via the genus field.

Author and date: If the subspecies field is used, then author and date refer to the subspecies name, if not, to the species name. The longest combination of authors likely to be encountered is Bucquoy, Dautzenberg & Dollfus. Author and date are sometimes combined as one field, as they are often cited together, but this can make it difficult to sort by date. Parentheses can be used around author and date in a combined field as needed, but this will also make it hard to sort: Reeve, 1848 and (Reeve, 1848) would alphabetize differently. A collector who intends to routinely sort the author field might consider using a yes/no field for parentheses to avoid this problem. The computer would then be programmed to print "(Author, Date)" if the field said yes and "Author, Date" otherwise.

Locality levels: Locality data are split into several fields to simplify computer searching and sorting. In addition to the fields listed here, the collector might want to specify fields for river or county if he anticipates sorting by that information. Note that the ocean field is left blank for land and freshwater species, except those on oceanic islands. Because political boundaries often do not correspond to natural geographic ones, it can sometimes be difficult to determine what information is appropriate for a particular locality field. For example, the Falkland Islands are currently a British possession, but are part of a different continent. Should United Kingdom be mentioned when a lot from the Falklands is catalogued? Similar questions arise with many island groups and territories. What is important is not whether the answer is yes or no, but that the answer be the same each time. For example, if you enter the Ryukyu Islands as a subdivision of Japan one time, don't enter them as an island group the next time, because you would then have to remember to search both the subdivision field and the country/island group field to find all the lots from the Ryukyus. Consistency is essential for a data base to work optimally.

Station number: If a collector maintains a field notebook, as discussed above, the station numbers used therein provide an easy way to generate lists of species collected at each location.

Size: This field is important primarily if the collector does not want to write catalogue numbers on specimens. The measurements of the specimen will help ensure that it is not accidentally separated from its data. Measurements are best made with calipers; models with dial and digital read-outs are available. If there are many specimens in a lot, their sizes are better recorded in the remarks field, to prevent the size field from growing too long. Collectors who exchange shells might use this field to record a range of sizes available for trade. They might also want a yes/no field that indicates if a given lot has specimens that they are willing to trade, and a field that tells the condition of specimens (Gem, Fine, Good, etc.).

Remarks: This field contains any information that does not readily fit in the other fields, such as collecting technique, or a list of previous owners of a specimen.

The above material has been adapted from Dr. Rosenberg's The Encyclopedia of Seashells, published by Robert Halt, Ltd., London, 1992. Dr. Rosenberg is Associate Curator of Malacology at the Academy of Natural Sciences of Philadelphia