84 THE NAUTILUS. 



structiou of dredges and other apparatus being especially full and 

 timely. More space should have been given to the methods of pre- 

 servation of the soft parts and naked mollusks, those in vogue among 

 collectors being very crude and by no means up to the times. 

 Altogether the brochure will be found very useful to active collect- 

 ors. 



Gould's ' North Pacific Exploring Expedition ' types. — 

 " Apropos of Mr. Marshall's note in the August Nautilus it may 

 be as well to state that practically all Gould's type specimens of the 

 " Wilkes " and " Ringgold and Rodgers" exploring expeditions are 

 to be found in the National collection. They were of course Govern- 

 ment property, but Dr. Gould who described them, for the most part 

 gratuitously, was permitted to retain as remuneration, duplicate spec- 

 imens for his own collection now at Albany. 80 of those species of 

 which there were duplicates there may be said to be two sets of 

 types. The uniques are in the National Museum. How Mr. Tryon 

 came to confuse these specimens with those illustrating the mollusk- 

 fauna of the eastern coast of the United States, which, with sundry 

 alcoholic specimens, were destroyed while loaned to Dr. Stimpson 

 at Chicago, I do not know ; but that they did not go to Chicago and 

 are at present in my ofScial custody is indubitable. — Dr. Wm. H. 

 Dall, Curator Dept. Moll., U. S. Nat. Museum, in letter to Ed. 



EXCHANGES. 



Wanted. Fine specimens of Lobsters, Crabs, Fiddler crabs. 

 Prawns, Shrimps, Marine, Land and Fresh-water shells. Offered 

 specimens of Marine, Land and Fresh-water shells. Please send list 

 and I will do the same in return. — Thomas Morgan, P. 0. Box 164, 

 Somerville, N. J. 



Offered. Land and Fresh-water shell from East Indies and 

 Ceylon, in exchange for Land and Fresh-water shells, from West 

 Indies, California, and Central America. — Miss Linter, Arragon 

 Close, Tivickeiiham, Middlesex, Eng. 



Wanted, Land Shells. Offer, twenty species of Kansas Fresh- 

 water Shells, including the rare Unio Aberti and Physa solida Lea, 

 and Land Shells and Cretaceous fossils. — Frank J. Ford, 314 

 Wabash Ave., Wichita, Kansas. 



