Mollusk Type Collection

When a new species is described, a single specimen must be designated as the holotype, or “type” of that species. These specimens exemplify the characteristics that distinguish this species from all others. Researchers refer to these types to verify a new species, study differences between species, or study unique adaptations of one species.

The Delaware Museum of Natural History has about 1,200 type specimens from the Phylum Mollusca.  To make the Museum’s collection accessible to researchers and the public, the type collection has been put online using Picasa, a photo storage and viewing application developed by Google.  Use this link to search the mollusk type collection on Picasa:

Numerous users search the thousands of pictures housed on Picasa.  Please follow the directions below for searching to be sure you get the desired results. Be sure to check the “omitted results” at the bottom of the page to see all the pictures from our collection that match your search.

Every search must begin with “DMNHmollusk.”  This limits your search of Picasa to only the Museum’s collection.

Following DMNHmollusk, type into the search bar what you would like to search for. You may search by class (e.g, bivalve, gastropod, or chiton), genus, species, country, author, or type (e.g., holotype, paratype, syntype), or any combination . Examples are below.

The photographs are organized by five pieces of information:

1. Genus

2. Species

3. Location

4. Author

5. Type (halotype, paratype, syntype, etc.)

Each photograph is accompanied by a GoogleMaps location.  This is a rough location based on town, region, and country names accompanying the specimen; the type collection has not been georeferenced and these are not exact locations.  Additional location data can be requested from Nasreen Aziz, Collections Manager.

When running a search, Google may omit some results in order to give you the most relevant picture matching your search.  Be sure to check the “omitted results” at the bottom of the page to see all the pictures from our collection that match your search.

The online type collection is to be used for educational and reference purposes only.  All pictures are the property of the Delaware Museum of Natural History and are not to be copied or used for commercial purposes without the consent of the Museum.  To request photographs of specimens, to schedule a time to view a specimen in the museum, or to ask questions about the collection, please contact Nasreen Aziz at

When searching Picasa, you will be directed off the Delaware Museum of Natural History’s website.  The Museum is not responsible for or associated with ads or other content that may appear on Picasa during the course of a search.


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